Patent Application
20250188703
The present disclosure relates to a work machine and a method of controlling a work machine.
In order to excavate soil in an amount desired by an operator of a work machine with a work implement, experiences and skills of the operator have conventionally been required. Therefore, a work machine that controls a posture of a work implement with a trained model has recently been developed.
For example, Japanese Patent Laying-Open No. 2021-143555 (PTL 1) discloses a wheel loader as such a work machine on which a computer is mounted, the computer obtaining a target value for an amount of a work performed by a work implement, a period of time elapsed since the work implement started to work, and mechanical data for operation of a body to which the work implement is attached and the work implement, using a trained posture estimation model to estimate a target posture from the target value, the elapsed period of time and the mechanical data, and thus outputting the estimated target posture.
In addition, a hydraulic mechanical transmission (HMT) wheel loader (NPL 1) utilizing electronic control has recently been developed. The HMT wheel loader utilizing electronic control achieves both of high work efficiency of a wheel loader of a type including a torque converter and a mechanical transmission and high operability of a wheel loader of a hydrostatic transmission (HST) type.
PTL 1: Japanese Patent Laying-Open No. 2021-143555
NPL 1: Takuya Muramoto et al., “Denshi Seigyo wo Katsuyou shita HMT (Hydraulic Mechanical Transmission) Hoiru Roda no Kaihatsu (Development of Hydraulic Mechanical Transmission (HMT) Wheel Loader Utilizing Electronic Control),” [online], 2020, Construction Contract and Construction Machine Symposium Articles and Synopsis, [Searched on Feb. 7, 2022], <URL: https://jcmanet.or.jp/bunken/symposium/2020/ronbun15.pdf>
Automatic scoop of a designated amount of soil by a work implement more accurate than in a conventional example has been demanded. The present disclosure provides a work machine and a method of controlling a work machine that allow automatic and accurate scoop of a designated amount of soil.
According to one aspect of the present disclosure, a work machine includes a vehicular body that can travel, a work implement including a bucket, the work implement performing an excavation work with the bucket, and a controller. The controller includes first calculation means for obtaining mechanical data on an operation of the vehicular body and the work implement and calculating a target posture of the work implement during the excavation work based on the mechanical data and second calculation means for calculating an accelerator opening necessary for excavation of a target amount of excavated soil. The controller controls the operation of the work implement such that a posture of the work implement is set to the target posture and controls travel of the vehicular body based on the accelerator opening. According to another aspect of the present disclosure, a method of controlling a
work machine including a vehicular body that can travel and a work implement including a bucket includes obtaining mechanical data on an operation of the vehicular body and the work implement and calculating a target posture of the work implement during an excavation work based on the mechanical data, calculating an accelerator opening necessary for excavation of a target amount of excavated soil, and controlling the operation of the work implement such that a posture of the work implement is set to the target posture and controlling travel of the vehicular body based on the accelerator opening.
According to the present disclosure, a designated amount of soil can automatically and accurately be scooped.
An embodiment will be described below with reference to the drawings. In the description below, the same elements have the same reference characters allotted and their labels and functions are also identical. Therefore, detailed description thereof will not be repeated.
A wheel loader 1 which is one type of a self-propelled work machine will be described in an embodiment by way of example of a work machine.
As shown in
Traveling apparatus 4 has vehicular body 20 travel and includes running wheels 4a and 4b. Wheel loader 1 can be self-propelled as running wheels 4a and 4b are rotationally driven, and can perform a desired work with work implement 3.
Vehicular body frame 2 includes a front frame 2a and a rear frame 2b. Front frame 2a and rear frame 2b are attached as being swingable in a lateral direction. A pair of steering cylinders 11 is attached across front frame 2a and rear frame 2b. Steering cylinder 11 is a hydraulic cylinder. As steering cylinder 11 is extended and contracted by hydraulic oil from a steering pump (not shown), a direction of travel of wheel loader 1 is laterally changed.
A direction of straight travel of wheel loader 1 is herein referred to as a fore/aft direction of wheel loader 1. In the fore/aft direction of wheel loader 1, a side on which work implement 3 is arranged with respect to vehicular body frame 2 is defined as a fore direction and a side opposite to the fore direction is defined as an aft direction. A lateral direction of wheel loader 1 is a direction orthogonal to the fore/aft direction in a plan view. A right side and a left side in the lateral direction when facing front are defined as a right direction and a left direction, respectively. An upward/downward direction of wheel loader 1 is a direction orthogonal to a plane defined by the fore/aft direction and the lateral direction. A side where the ground is located in the upward/downward direction is defined as a lower side and a side where the sky is located is defined as an upper side.
Work implement 3 and a pair of running wheels (front wheels) 4a are attached to front frame 2a. Work implement 3 is disposed in front of vehicular body 20. Work implement 3 is driven by hydraulic oil from a work implement pump 13 (see
Boom 14 has a base end portion rotatably attached to front frame 2a by a boom pin 9. Bucket 6 is rotatably attached to boom 14 by a bucket pin 17 located at the tip end of boom 14.
Front frame 2a and boom 14 are coupled to each other by a pair of boom cylinders 16. Boom cylinder 16 is a hydraulic cylinder. Boom cylinder 16 has a base end attached to front frame 2a. Boom cylinder 16 has a tip end attached to boom 14. As boom cylinder 16 is extended and contracted by hydraulic oil from work implement pump 13 (see
Work implement 3 further includes a bell crank 18, a bucket cylinder 19, and a link 15. Bell crank 18 is rotatably supported on boom 14, by a support pin 18a located substantially in the center of boom 14. Bucket cylinder 19 couples bell crank 18 and front frame 2a to each other. Link 15 is coupled to a coupling pin 18c provided at a tip end portion of bell crank 18. Link 15 couples bell crank 18 and bucket 6 to each other.
Bucket cylinder 19 is a hydraulic cylinder and a work tool cylinder. Bucket cylinder 19 has a base end attached to front frame 2a. Bucket cylinder 19 has a tip end attached to a coupling pin 18b provided at a base end portion of bell crank 18. As bucket cylinder 19 is extended and contracted by hydraulic oil from work implement pump 13 (see
Cab 5 and a pair of running wheels (rear wheels) 4b are attached to rear frame 2b. Cab 5 is arranged in the rear of boom 14. Cab 5 is carried on vehicular body frame 2. In cab 5, a seat where an operator of wheel loader 1 is seated, an operation apparatus 8 which will be described later, and the like are arranged.
Engine 21 is, for example, a diesel engine. Output from engine 21 is controlled by adjustment of an amount of fuel to be injected into a cylinder. This adjustment is made by control of an electronic governor (not shown) by controller 10.
An engine rotation speed is detected by an engine rotation speed sensor 91. A detection signal from engine rotation speed sensor 91 is inputted to controller 10.
Traveling apparatus 4 is an apparatus that has wheel loader 1 travel with driving force from engine 21. Traveling apparatus 4 includes a transmission 23 and front wheel 4a and rear wheel 4b described above.
Transmission 23 which is a power transmission apparatus is an apparatus that transmits driving force from engine 21 to front wheel 4a and rear wheel 4b. In wheel loader 1, both of front wheel 4a attached to front frame 2a and rear wheel 4b attached to rear frame 2b serve as drive wheels that have wheel loader 1 travel by receiving driving force. Transmission 23 changes a speed of rotation of an input shaft 27 and outputs the rotation to an output shaft 28.
An output rotation speed sensor 92 is provided in output shaft 28. Output rotation speed sensor 92 detects a rotation speed of output shaft 28. A detection signal from output rotation speed sensor 92 is inputted to controller 10. Controller 10 calculates a vehicle speed based on the detection signal from output rotation speed sensor 92.
Driving force outputted from transmission 23 is transmitted to wheels 4a and 4b through an axle 32 or the like. Wheel loader 1 thus travels. Some of driving force from engine 21 is transmitted to traveling apparatus 4 so that wheel loader 1 travels.
Some of driving force from engine 21 is transmitted to work implement pump 13 through a motive power extraction unit 33.
Work implement pump 13 and a steering pump are hydraulic pumps driven by driving force from engine 21. Hydraulic oil delivered from work implement pump 13 is supplied to boom cylinder 16 and bucket cylinder 19 through a work implement valve 34. Work implement 3 is driven by some of driving force from engine 21.
A first hydraulic pressure detector 95 is attached to boom cylinder 16. First hydraulic pressure detector 95 detects a pressure of hydraulic oil in an oil chamber of boom cylinder 16. A detection signal from first hydraulic pressure detector 95 is inputted to controller 10.
A second hydraulic pressure detector 96 is attached to bucket cylinder 19. Second hydraulic pressure detector 96 detects a pressure of hydraulic oil in an oil chamber of bucket cylinder 19. A detection signal from second hydraulic pressure detector 96 is inputted to controller 10.
A first angle detector 29 is, for example, a potentiometer attached to boom pin 9. First angle detector 29 detects a boom angle representing an angle of lift of boom 14 from vehicular body 20. First angle detector 29 outputs a detection signal indicating the boom angle to controller 10.
Specifically, as shown in
First angle detector 29 may be a stroke sensor arranged in boom cylinder 16.
A second angle detector 48 is, for example, a potentiometer attached to support pin 18a. Second angle detector 48 detects a bell crank angle representing an angle of bell crank 18 with respect to boom 14. Second angle detector 48 outputs a detection signal indicating the bell crank angle to controller 10.
Specifically, as shown in
Second angle detector 48 may detect an angle (a bucket angle θ3) of bucket 6 with respect to boom 14. Bucket angle θ3 is an angle formed between a straight line R that passes through the center of bucket pin 17 and a cutting edge 6a of bucket 6 and boom reference line P. In a triangle UdUfUe (not shown) having a position (which is also referred to as “Ud” below) of cutting edge 6a of bucket 6, an intersection (“Uf”) between boom reference line P and straight line R, and a point (which is also referred to as “Ue” below) located on reference line P and located opposite to the center (Uc) of boom pin 9 with respect to the intersection as vertices, bucket angle θ3 is expressed as ∠UdUfUe.
Second angle detector 48 may be a potentiometer or a proximity switch attached to bucket pin 17. Alternatively, second angle detector 48 may be a stroke sensor arranged in bucket cylinder 19.
Operation apparatus 8 is operated by the operator. Operation apparatus 8 includes a plurality of types of operation members operated by the operator to operate wheel loader 1. Specifically, operation apparatus 8 includes an accelerator operation member 81a, a boom operation member 83a, and a bucket operation member 84a.
Accelerator operation member 81a is, for example, an accelerator pedal. With increase in amount of operation (amount of pressing in the case of the accelerator pedal) onto accelerator operation member 81a, vehicular body 20 accelerates. With decrease in amount of operation onto accelerator operation member 81a, vehicular body 20 decelerates. An accelerator operation detection unit 81b detects an amount of operation onto accelerator operation member 81a. The amount of operation onto accelerator operation member 81a is also referred to as an “accelerator opening” or an “accelerator operation amount.” Accelerator operation detection unit 81b detects the accelerator opening (which is also referred to as an “accelerator opening V1” below). Accelerator operation detection unit 81b outputs a detection signal to controller 10. Controller 10 controls output from engine 21 and a reduction ratio of transmission 23 based on the detection signal from accelerator operation detection unit 81b.
Accelerator operation detection unit 81b is, for example, a sensor that reads a voltage value (operation signal) based on an accelerator operation. Accelerator operation detection unit 81b may be a device mounted in advance on wheel loader 1. Alternatively, accelerator operation detection unit 81b may be a device subsequently attached to vehicular body 20. Accelerator operation detection unit 81b is also referred to as an “accelerator opening sensor.”
Boom operation member 83a is operated to operate boom 14. Boom operation member 83a is, for example, a control lever. A boom operation detection unit 83b detects a position of boom operation member 83a. Boom operation detection unit 83b outputs a detection signal to controller 10. Controller 10 controls work implement valve 34 based on the detection signal from boom operation detection unit 83b. As boom cylinder 16 extends and contracts, boom 14 operates.
Boom operation detection unit 83b is, for example, a sensor that reads a voltage value (operation signal) based on a lever operation. Boom operation detection unit 83b may be a device mounted in advance on wheel loader 1. Alternatively, boom operation detection unit 83b may be a device subsequently attached to vehicular body 20.
Bucket operation member 84a is operated to operate bucket 6. Bucket operation member 84a is, for example, a control lever. A bucket operation detection unit 84b detects a position of bucket operation member 84a. Bucket operation detection unit 84b outputs a detection signal to controller 10. Controller 10 controls work implement valve 34 based on the detection signal from bucket operation detection unit 84b. As bucket cylinder 19 extends and contracts, bucket 6 operates. Bucket operation detection unit 84b is, for example, a sensor that reads a voltage value (operation signal) based on a lever operation. Bucket operation detection unit 84b may be a device mounted in advance on wheel loader 1. Alternatively, bucket operation detection unit 84b may be a device subsequently attached to vehicular body 20.
Display 50 shows various types of information upon receiving an input of a command signal from controller 10. The various types of information shown on display 50 may be, for example, information on works performed by wheel loader 1, vehicular body information on a remaining amount of fuel, a temperature of coolant, and a temperature of hydraulic oil, a peripheral image obtained by imaging of surroundings of wheel loader 1, and a measurement value from a payload meter 99 (
An operation key 51 is an input device. Operation key 51 is a device for input of various types of information to controller 10 by the operator. The operation key may be implemented as a software key. Specifically, wheel loader 1 may include as the input device, a touch screen in which a touch panel is layered on display 50. In this case, a signal generated by touching onto a part of display 50 by the operator is outputted from the touch screen to controller 10. Operation key 51 does not have to be provided in a vehicle. Operation key 51 may be an external terminal. Controller 10 includes a calculator 150 and a calculator 280. Calculator 150
obtains mechanical data on operations of vehicular body 20 and work implement 3 and calculates a target posture of work implement 3 during an excavation work based on the mechanical data. The mechanical data includes a pressure of boom cylinder 16, a vehicle speed of wheel loader 1, a rotation speed of engine 21, and traction force of wheel loader 1. Calculator 150 includes an obtaining unit 170 and a trained model 180. Obtaining unit 170 obtains the mechanical data on the operations of vehicular body 20 and work implement 3. Trained model 180 receives as an input, the mechanical data obtained by obtaining unit 170. A function of trained model 180 and a function of calculator 280 will be described later.
Controller 10 is implemented generally by reading of various programs by a central processing unit (CPU). Controller 10 includes a memory 10M. Memory 10M functions as a work memory, and various programs for performing the functions of the wheel loader are stored therein. At least a bucket volume of bucket 6 attached to wheel loader 1 and trained model 180 are stored in memory 10M.
Controller 10 recognizes an operation by the operator onto accelerator operation member 81a, boom operation member 83a, and bucket operation member 84a and a vehicle state such as a load onto work implement 3 and a vehicle speed, and electronically controls hydraulic motors 232 and 233 in transmission 23 and engine 21. Controller 10 can calculate an amount of fuel consumption per unit operation time of engine 21, an amount of fuel consumption per unit travel distance of wheel loader 1, and an amount of fuel consumption per unit payload in bucket 6, based on an amount of fuel supply to engine 21.
Controller 10 calculates the vehicle speed of wheel loader 1 based on the detection signal from output rotation speed sensor 92. Controller 10 reads a map that defines relation between the vehicle speed and traction force of wheel loader 1 from memory 10M and calculates traction force based on the map. Controller 10 receives input of the detection signal indicating the engine rotation speed from engine rotation speed sensor 91. Controller 10 reads a map that defines relation between the engine rotation speed and engine torque from the memory and calculates engine torque based on the map.
Traction force and engine torque may be calculated in a manner different from reference to the map. Traction force and engine torque may be calculated, for example, by reference to a table or computation by using a function. Controller 10 automatically controls operations of boom 14 and bucket 6. Details of this automatic control will be described later.
Transmission 23 will now be described in further detail. Transmission 23 is a hydraulic mechanical transmission that utilizes electronic control in the present example. Transmission 23 includes a planetary gear mechanism 231 and hydraulic motors 232 and 233.
Transmission 23 continuously shifts a gear based on combination of planetary gear mechanism 231 and two hydraulic motors 232 and 233. Planetary gear mechanism 231 includes a ring gear, a carrier, a sun gear, and a planetary gear. Motive power is transmitted from the ring gear, the carrier, and the sun gear to the outside. Transmission 23 has the carrier connected to engine 21, has the ring gear connected to hydraulic motor 233, and has the sun gear connected to hydraulic motor 232 and axle 32. Planetary gear mechanism 231 and components 21, 32, 232, and 233 are connected to one another as being decelerated.
Transmission 23 computes a target engine rotation speed necessary for travel and a vehicle speed request made by an operation by the operator, and sets a reduction ratio as the transmission by electronic control of two hydraulic motors 232 and 233.
Utilizing characteristics of a continuously variable transmission function, transmission 23 separates control of the rotation speed of engine 21 and operations onto accelerator operation member 81a from each other. Such control that the speed of work implement 3 is controlled only with a work implement lever (boom operation member 83a and bucket operation member 84a) and the vehicle speed is controlled only with accelerator operation member 81a (independent control of the work implement and travel) is thus achieved.
When the operator operates the work implement lever in order to quickly move work implement 3, controller 10 computes a pump flow rate for achieving a necessary work implement speed and calculates a target engine rotation speed based on a size of mounted work implement pump 13 (processing (iii)). Engine 21 is controlled by controller 10 based on the target rotation speed, regardless of an accelerator pedal operation. In other words, the engine rotation speed is automatically controlled based on the work implement lever operation.
On the other hand, in order to meet the vehicle speed request recognized through accelerator operation member 81a, controller 10 computes the reduction ratio required for transmission 23. The reduction ratio is obtained by computing a ratio between the engine rotation speed determined by the work implement lever operation and the vehicle speed request determined by the accelerator pedal operation. Transmission 23 enables travel in accordance with the vehicle speed request from the operator by electronic control of two hydraulic motors 232 and 233 for realizing the target reduction ratio.
In such wheel loader 1, by independent control of the work implement and travel, the work implement speed and the vehicle speed are controllable independently of each other, and simple and intuitive operability can be achieved. Since the configuration of HMT utilizing electronic control has already been known, further detailed description will not be provided.
Wheel loader 1 performs an excavation work to scoop an excavation target such as soil.
As shown in
Wheel loader 1 performs an excavation operation to scoop excavation target 100 in bucket 6 and a loading operation to load loads (excavation target 100) in bucket 6 onto a load target (transport machine) such as a dump truck.
More specifically, wheel loader 1 excavates excavation target 100 and loads excavation target 100 onto the load target by successively repeating a plurality of work steps as below. The dump truck will be described below by way of example of the load target.
A first step is an unloaded forward travel step of traveling forward toward excavation target 100. A second step is an excavation step (plowing) of penetrating cutting edge 6a of bucket 6 into excavation target 100 and moving wheel loader 1 forward until a prescribed amount of excavation target 100 enters bucket 6. A third step is an excavation step (scooping) of moving bucket 6 upward by operating boom cylinder 16 and tilting back bucket 6 by operating bucket cylinder 19. A fourth step is a loaded rearward travel step of moving wheel loader 1 rearward after excavation target 100 is scooped in bucket 6.
A fifth step is a loaded forward travel step of moving wheel loader 1 forward to be closer to the dump truck while a state that bucket 6 has been moved upward is maintained or while bucket 6 is being moved upward. A sixth step is a soil ejection step of dumping bucket 6 at a prescribed position to load excavation target 100 on a platform of the dump truck. A seventh step is a rearward travel and boom lowering step of lowering boom 14 and returning bucket 6 to an excavation posture while wheel loader 1 is moved rearward. The steps above are typical work steps that make up one cycle of excavation and loading works.
Whether the current work step of wheel loader 1 falls under the excavation step and work implement 3 is performing the excavation work or otherwise can be determined, for example, by using combination of criteria about an operation signal based on the operation by the operator to move wheel loader 1 forward and rearward, an operation signal based on the operation by the operator onto work implement 3, and a current hydraulic pressure of the cylinder of work implement 3.
In step S3, controller 10 determines whether or not it has received input of a total amount of soil to be loaded on the dump truck. The input is provided through operation key 51 serving as the input device. When controller 10 determines that it has received input of the total amount of soil (YES in step S3), in step S4, it calculates a target amount of excavated soil. Controller 10 calculates the amount of soil per one excavation as the target amount of excavated soil.
For example, when the inputted total amount of soil is 30 ton and the bucket volume (maximum volume) of bucket 6 is 7 ton, controller 10 sets the target amount of excavated soil to 6 ton by way of example. In this case, wheel loader 1 performs the excavation work five times in order to load a total of 30 ton (=6 ton×5 times) on the dump truck.
Though the target amount of excavated soil is set to the same value (equal) in five times of excavation work in this example, the target amount of excavated soil is not limited as such. For example, controller 10 may set the target amount of excavated soil in initial four times of excavation work to 7 ton which is equal to the bucket volume and may set the target amount of excavated soil in the last fifth time of excavation work to 2 ton which is the remaining amount.
When the total amount of soil to be loaded on the dump truck is equal to or less than the bucket volume, controller 10 may set the target amount of excavated soil to be the same as the total amount of soil. Alternatively, controller 10 may set the target amount of excavated soil to an amount calculated by dividing the total amount of soil.
When controller 10 determines that it has not received input of the total amount of soil (NO in step S3), it has the process proceed to step S11. In step S11, controller 10 determines whether or not it has received an engine stop operation. When controller 10 determines that it has received the engine stop operation (YES in step S11), it stops engine 21 and quits a series of processing. When controller 10 determines that it has not received the engine stop operation (NO in step S11), it has the process proceed to step S2.
After step S4, in step S5, controller 10 determines whether or not accelerator operation member 81a has been operated. Controller 10 makes this determination based on accelerator opening V1 detected by accelerator operation detection unit 81b.
When controller 10 determines that accelerator operation member 81a has been operated (YES in step S5), in step S6, controller 10 determines whether or not the excavation work has been started. Controller 10 determines whether or not the excavation work has been started based on the boom angle, an angle of the cutting edge of bucket 6, a boom bottom pressure, the vehicle speed, and a stroke of the control lever of boom 14. When controller 10 determines that accelerator operation member 81a has not been operated (NO in step S5), it has the process proceed to step S2.
When controller 10 determines that the excavation work has been started (YES in step S6), in step S7, it carries out automatic control of the work implement operation and the accelerator operation. In automatic control, controller 10 automatically controls a posture of work implement 3 and automatically controls travel (vehicle speed) of wheel loader 1 regardless of the amount of operation onto accelerator operation member 81a (that is, detected accelerator opening V1). During automatic control from step S7 to step S10 which will be described later, the operator is performing the operation onto accelerator operation member 81a (accelerator operation). While the accelerator operation is being performed, controller 10 automatically controls the work implement operation and the accelerator operation. Details of processing in step S7 will be described later.
In step S8, controller 10 determines whether or not accelerator operation member 81a is being operated. Controller 10 determines whether or not accelerator operation member 81a is kept pressed. Controller 10 determines whether or not the accelerator operation is being performed based on accelerator opening V1 detected by accelerator operation detection unit 81b. When controller 10 determines that accelerator operation member 81a is being operated (YES in step S8), in step S9, it determines whether or not bell crank angle θ2 has been maximized. A state in which bell crank angle θ2 has been maximized refers to a state in which soil in an amount corresponding to the target amount of excavated soil has been scooped in bucket 6 and the excavation step has ended.
When controller 10 determines that the operator is not performing the operation onto accelerator operation member 81a (NO in step S8), in step S10, it quits automatic control of the work implement operation and the accelerator operation. When the operator quits the operation onto accelerator operation member 81a, controller 10 quits automatic control and makes transition to manual control (step S2) on condition that it has not received the operation to stop engine 21.
When controller 10 determines that bell crank angle θ2 has been maximized (YES in step S9), it has the process proceed to step S10. When controller 10 determines that bell crank angle θ2 has not been maximized (NO in step S9), it has the process proceed to step S7.
Thus, when controller 10 determines that the accelerator operation is not being performed based on accelerator opening V1 detected by accelerator operation detection unit 81b or when the angle of bell crank 18 with respect to boom 14 has been maximized, controller 10 quits control of the operation of work implement 3 with trained model 180 and control of the operation of vehicular body 20 based on the calculated accelerator opening. The accelerator operation determined as not being performed means that accelerator opening VI has become equal to or smaller than a prescribed value.
The flow of processing performed in wheel loader 1 is not limited to the flow shown in
Specifically, when affirmative determination is made in step S8A (YES in step S8A), controller 10 has the process proceed to step S10. When negative determination is made in step S8A (NO in step S8A), controller 10 has the process proceed to step S9A. When affirmative determination is made in step S9A (YES in step S9A), controller 10 has the process proceed to step S7. When negative determination is made in step S9A (NO in step S9A), controller 10 has the process proceed to step S10.
Thus, in the present modification, controller 10 performs step S8 and step S9 in
Automatic control (step S7 in
Trained model 180 includes a neural network. The neural network includes an input layer 181, an intermediate layer (hidden layer) 182, and an output layer 183. Intermediate layer 182 is multi-layered.
Trained model 180 is artificial intelligence for determining a target posture of work implement 3 during the excavation work. Trained model 180 calculates the target posture from mechanical data on operations of vehicular body 20 and work implement 3 obtained by obtaining unit 170. Trained model 180 is trained (configured) to output as the target posture, the posture that allows scoop in bucket 6, of excavation target 100 in an amount corresponding to the bucket volume (that is, the maximum volume of bucket 6).
Specifically, trained model 180 calculates an amount of change 401 per unit time in boom angle θ1 and an amount of change Δθ2 per unit time in bell crank angle θ2 based on the boom cylinder pressure, the vehicle speed, the engine rotation speed, and traction force. Specifically, the boom cylinder pressure, the vehicle speed, the engine rotation speed, and traction force are inputted to trained model 180 every prescribed control cycle T, and trained model 180 outputs amount of change Δθ1 per unit time in boom angle θ1 and amount of change Δθ2 per unit time in bell crank angle θ2 as results of estimation.
Controller 10 controls the posture of work implement 3 based on calculated amounts of change Δθ1 and Δθ2. Specifically, controller 10 controls the posture of boom 14 based on amount of change Δθ1. Controller 10 controls the posture of bucket 6 based on amount of change Δθ2.
Trained model 180 is generated by using a training data set. The training data set includes a plurality of pieces of training data. Each piece of training data includes as input data, the boom cylinder pressure, the vehicle speed, the engine rotation speed, and traction force, and includes as ground truth data (training data), amount of change Δθ1 per unit time in boom angle θ1 and amount of change Δθ2 per unit time in bell crank angle θ2.
A parameter for the training model is sequentially updated based on an error between the output obtained at the time of input of the input data into the trained model and the ground truth data. The parameter is updated with the use of a training program. By repetition of such an updating operation (training), trained model 180 is generated. Specifically, trained model 180 is created from data on the same vehicle rank and the same quality of soil. The trained model may be generated by the controller of the wheel loader or an externa computer.
Calculator 280 calculates an accelerator opening (which is also referred to as an “accelerator opening V2” below) based on the target amount of excavated soil. When calculator 280 receives input of the target amount of excavated soil, it outputs accelerator opening V2. Specifically, when the target amount of excavated soil is designated, calculator 280 calculates accelerator opening V2 necessary for excavation of the target amount of excavated soil.
Calculator 280 calculates accelerator opening V2 necessary for excavation of the target amount of excavated soil based on a prescribed algorithm, separately from accelerator opening V1 detected by accelerator operation detection unit 81b. Calculator 280 sequentially receives accelerator opening V1 from accelerator operation detection unit 81b and separately calculates accelerator opening V2 necessary for excavation of the target amount of excavated soil. “Accelerator opening V2 necessary for excavation of the target amount of excavated soil” means the accelerator opening originally to be received by controller 10 from accelerator operation detection unit 81b (an amount of accelerator operation to originally be performed by the operator) in excavation of the target amount of excavated soil.
One accelerator opening V2 (constant value) is calculated for one target amount of excavated soil. For example, a numerical value u1 (0<u1≤1) is calculated as accelerator opening V2 for a target amount of excavated soil of 6 ton and a numerical value u2 (0<u2<u1) is calculated as accelerator opening V2 for a target amount of excavated soil of 2 ton.
When the target amount of excavated soil (ton) is designated (inputted), average boom bottom pressure calculator 281 calculates an average boom bottom pressure (Mpa). Specifically, average boom bottom pressure calculator 281 calculates the average boom bottom pressure (which is also referred to as a “target boom cylinder pressure” below) from the target amount of excavated soil, based on a function (y=ax2+bx+c . . . (f1)) expressing relation between the target amount of excavated soil (x) and the average boom bottom pressure (y). Average boom bottom pressure calculator 281 sends the calculated average boom bottom pressure to average traction force calculator 282 and accelerator opening calculator 283.
Function f1 is generated with a least square method based on several ten thousand pieces of data (amounts of excavated soil (specifically, measurement values from the payload meter) and an average value of boom bottom pressures in the case of the amount of excavated soil) obtained by a vehicle the same in vehicle rank as wheel loader 1, with regard to soil of the same quality. A black circle in the graph represents each piece of data.
When average traction force calculator 282 receives input of the average boom bottom pressure (ton), it calculates average traction force (N). Specifically, average traction force calculator 282 calculates average traction force (which is also referred to as “target traction force” below) from the average boom bottom pressure, based on a function (y=a′x2+b′x+c′ . . . (f2)) expressing relation between the average boom bottom pressure (x) and average traction force (y). Average traction force calculator 282 sends calculated average traction force to accelerator opening calculator 283.
Function f2 is generated with the least square method based on several ten thousand pieces of data (the average value of the boom bottom pressures during the excavation work and average traction force during the excavation work) obtained by a vehicle the same in vehicle rank as wheel loader 1, with regard to soil of the same quality. A black circle in the graph represents each piece of data.
When accelerator opening calculator 283 receives input of the average boom bottom pressure and average traction force, it calculates accelerator opening V2. Specifically, accelerator opening calculator 283 calculates accelerator opening V2 from the average boom bottom pressure and average traction force, based on a function (Z=Ax+By . . . (f3)) expressing relation among the average boom bottom pressure (x), average traction force (y), and the accelerator opening (z). In the present example, the average boom bottom pressure and the average traction force are normalized. In the present example, coefficients A and B are each not smaller than 0 and not larger than 1.
Coefficients A and B in function f3 are determined based on multiple regression analysis. Accelerator opening calculator 283 thus predicts the accelerator opening which is one objective variable based on the average boom bottom pressure and the average traction force which are explanatory variables. Function f1, function f2, and function f3 are stored in memory 10M.
Accelerator opening calculator 283 outputs calculated accelerator opening V2. In this case, controller 10 controls travel of vehicular body 20 based on calculated accelerator opening V2. Controller 10 thus has the vehicular body travel (travel forward) at a speed in accordance with calculated accelerator opening V2.
The reason why controller 10 calculates accelerator opening V2 based on the target amount of excavated soil as above is as below. As described above, trained model 180 determines the posture of work implement 3 in the excavation work. Controller 10 controls work implement 3 to operate in the determined posture.
Trained model 180 is configured such that work implement 3 is in the posture in which it can scoop in bucket 6, excavation target 100 in the amount corresponding to the bucket volume. Therefore, controller 10 controls travel (vehicle speed) of vehicular body 20 based on calculated accelerator opening V2 to adjust the amount of soil to be scooped in bucket 6.
Specifically, in order to realize the vehicle speed based on calculated accelerator opening V2, controller 10 computes the reduction ratio required in transmission 23.
The reduction ratio is obtained by computing a ratio between the engine rotation speed determined in automatic control of work implement 3 and the vehicle speed request determined based on calculated accelerator opening V2. As transmission 23 operates at the reduction ratio, the amount of soil scooped in bucket 6 is adjusted. In wheel loader 1, as calculated accelerator opening V2 is smaller, the amount of scooped excavation target 100 is smaller.
Specifically, when the accelerator opening is small, an amount of penetration into the ground is also small. Therefore, an amount of earthmoving (amount of excavated soil) in excavation is small (see
The target posture determined by trained model 180 is defined as the “posture in which the work implement can scoop excavation target 100 in the amount corresponding to the bucket volume” above. The target posture, however, is by way of example and is not limited thereto. For example, the target posture determined by trained model 180 may be a “posture in which the work implement can scoop excavation target 100 in an amount corresponding to 90% of the bucket volume” or a “posture in which the work implement can scoop excavation target 100 in an amount corresponding to 50% of the bucket volume.”
Calculator 280 calculates a throttle position from the target amount of excavated soil, based on function f3 obtained in multiple regression analysis above. Without being limited as such, calculator 280 may be implemented by a trained program (for example, a neural net).
For example, in an example where the bucket volume is 7 ton and a designated (calculated) target amount of excavated soil is 7 ton, wheel loader 1 can scoop substantially 7 ton of soil.
Wheel loader 1 thus controls the operation of work implement 3 such that the posture of work implement 3 is set to the target posture by using trained model 180 and controls travel of vehicular body 20 based on accelerator opening V2 calculated based on the target amount of excavated soil, to thereby excavate the amount of soil corresponding to the target amount of excavated soil.
Advantages of wheel loader 1 will specifically be described below based on experimental results.
Similarly, errors in examples where the target amounts of excavated soil were 6.3 ton, 5.6 ton, 4.9 ton, 4.2 ton, and 3.5 tons were 0.0%, 1.8%, 0.0%, 2.4%, and 8.6%, respectively. Thus, in any case, the error was confirmed as being accommodated within a range not higher than 10.0%.
As shown in
onto the dump truck is 11.2 ton, when soil is excavated by 5.6 ton each time, the total fuel economy is 55.2 ml (=27.6×2). On the other hand, when 7.0 ton of soil is excavated and thereafter 4.2 ton of soil is excavated and loaded onto the dump truck, the total fuel economy is 90.4 ml (=66.5+23.9).
It was thus found that, in calculation of the target amount of excavated soil from the total amount of soil to be loaded on the dump truck, from a point of view of fuel economy, the amount of excavated soil is preferably averaged.
(1) Wheel loader 10 includes vehicular body 20 that can travel, work implement 3 including bucket 6, work implement 3 performing an excavation work with bucket 6, and controller 10. Controller 10 includes calculator 150 that obtains mechanical data on an operation of vehicular body 20 and work implement 3 and calculates a target posture of work implement 3 during the excavation work based on the mechanical data and calculator 280 that calculates accelerator opening V2 necessary for excavation of a target amount of excavated soil. In the present example, calculator 150 includes obtaining unit 170 that obtains the mechanical data and trained model 180 that calculates the target posture of the work implement during the excavation work based on the mechanical data. Controller 10 controls the operation of work implement 3 such that a posture of work implement 3 is set to the target posture and controls travel of vehicular body 20 based on accelerator opening V2.
According to such a configuration, when the target amount of excavated soil is designated, calculator 280 calculates accelerator opening V2 necessary for excavation of the target amount of excavated soil. Therefore, wheel loader 1 controls the operation of work implement 3 to set the target posture obtained by trained model 180 and travels based on accelerator opening V2 calculated by calculator 280, so that it can automatically and accurately scoop the designated target amount of excavated soil.
Specifically, the target posture obtained by trained model 180 is the same regardless of magnitude of accelerator opening V2. Even when the target posture is the same, the amount of excavated soil can be controlled by control of the amount of penetration of bucket 6 into the ground, that is, the accelerator opening. Typically, the amount of excavated soil is varied by the amount of penetration into the ground, that is, the accelerator opening (vehicle speed) and the work implement speed. In the configuration of the present embodiment, however, the target posture controlled by trained model 180 includes also control of the work implement speed. In other words, when the target posture is the same, variation in work implement speed is also common. Therefore, the amount of excavated soil can be controlled only by control of the accelerator opening (vehicle speed). Strictly, the work implement speed determined by trained model 180 is varied also with the vehicle speed. Specifically, the work implement speed is determined to be higher as the vehicle speed is lower. The work implement speed, however, is affected also by a variable (the boom cylinder pressure, the engine rotation speed, or traction force) other than the vehicle speed. Therefore, variation in work implement speed with variation in vehicle speed is small. In other words, variation in amount of excavation into the ground with variation in vehicle speed is larger than variation in work implement speed with variation in vehicle speed. Therefore, the amount of excavated soil can be controlled based on the accelerator opening (vehicle speed). Accuracy can further be improved by correction in consideration of variation in work implement speed with variation in vehicle speed. Specifically, correction can be made with a method as in a later-described modification where quality of soil changes. As set forth above, even when the target posture of work implement 3 is the same, the amount of excavated soil is freely controllable based on the accelerator opening. By thus controlling accelerator opening V2, the amount of excavated soil can be adjusted.
(2) Work implement 3 includes boom 14 and boom cylinder 16 that operates boom 14. As described with reference to
(3) Vehicular body 20 further includes engine 21. The mechanical data includes a pressure of boom cylinder 16, a vehicle speed of wheel loader 1, a rotation speed of engine 21, and traction force of wheel loader 1. According to such a configuration, trained model 180 can output the target posture of work implement 3 based only on four input parameters.
(4) Work implement 3 further includes bell crank 18 that pivotably supports boom 14. When controller 10 determines that an accelerator operation is not being performed based on accelerator opening V1 detected by accelerator operation detection unit 81b or when an angle of bell crank 18 with respect to boom 14 has been maximized, controller 10 quits control of the operation of work implement 3 with trained model 180 and control of the operation of vehicular body 20 based on calculated accelerator opening V2.
According to such a configuration, end of one excavation work can be determined. In addition, control of the operation of work implement 3 with trained model 180 and control of the operation of vehicular body 20 based on calculated accelerator opening V2 can be terminated based on determination as end of one excavation work.
(5) Controller 10 receives an input of a total weight of soil (excavation target) to be loaded on the dump truck through an input device such as operation key 51. When the total weight is larger than the bucket volume, controller 10 divides the total weight into a plurality of weights equal to or less than the bucket volume. Controller 10 (specifically, calculator 280) calculates accelerator opening V2 with the weight obtained by division being set as the target amount of excavated soil. According to such a configuration, when a total weight of soil to be loaded onto the dump truck is inputted, the target amount of excavated soil is calculated. Therefore, the operator should only input the total weight.
(6) Preferably, controller 10 equally divides the total weight. According to such a configuration, fuel economy of wheel loader 1 can be lower than in an example where the total weight is not equally divided.
(1) When quality of soil to be excavated changes, accuracy of calculator 280 is expected to lower. In an example where the target amount of excavated soil is designated to 3 ton, 4 ton of soil may be excavated. A configuration of calculator 280 that performs an adjustment function (tuning function) that allows output of accelerator opening V2 in accordance with the quality of soil will now be described. Calculator 280 that performs such an adjustment function is referred to as a calculator 280A below for the sake of convenience of description.
Generation of a correction expression by correction unit 284 will initially be described. Thereafter, correction of the target amount of excavated soil with the correction expression by correction unit 284 will be described.
Correction unit 284 receives input of the target amount of excavated soil and a weight (measurement value) of soil detected by payload meter 99 mounted on wheel loader 1. Correction unit 284 generates the correction expression from the target amount of excavated soil and an actual amount of excavated soil (measurement value). Specifically, correction unit 284 generates the correction expression using three pieces of data which will be described later (specifically, three coordinate values (x1, y1), (x2, y2), and (x3, y3)). Payload meter 99 is an exemplary detection unit that detects the weight of excavation target 100 loaded in bucket 6. Payload meter 99 may be mounted on wheel loader 1 in advance or subsequently attached to wheel loader 1.
As shown in
As shown in
In step S23, controller 10 has the excavation work performed under automatic control described above, with the target amount of excavated soil being set to a second amount of soil (x2) (>x1). In this case, the accelerator opening is larger (“accelerator opening: middle”) than when the target amount of excavated soil is set to the first amount of soil (x1). In step S24, controller 10 obtains the measurement value (y2) from payload meter 99 at the time when the target amount of excavated soil is set to the second amount of soil (x2).
In step S25, controller 10 has the excavation work performed under automatic control described above, with the target amount of excavated soil being set to a third amount of soil (x3) (>x2). In this case, the accelerator opening is larger (“accelerator opening: large”) than when the target amount of excavated soil is set to the second amount of soil (x2). In step S26, controller 10 obtains the measurement value (y3) from payload meter 99 at the time when the target amount of excavated soil is set to the third amount of soil (x3).
In step S27, controller 10 generates a function (x=αy2+βy+γ . . . (f4)) with the least square method based on the three coordinate values (x1, y1), (x2, y2), and (x3, y3).
Controller 10 may determine the first amount of soil (x1), the second amount of soil (x2), and the third amount of soil (x3) as appropriate. Alternatively, function f4 may be generated from two or less amounts of soil (for example, x1 and/or x2) or four or more amounts of soil (x1, x2, x3, x4, . . . ).
When correction unit 284 generates function f4 described above, it has function f4 stored. Thereafter, an actual operation using function f4 is performed. Though details will be described later, correction unit 284 corrects the inputted target amount of excavated soil with function f4. Correction unit 284 sends the corrected target amount of excavated soil to average boom bottom pressure calculator 281. In the actual operation, calculator 280A does not use the measurement value from payload meter 99 in calculation of accelerator opening V2.
Average boom bottom pressure calculator 281 calculates the average boom bottom pressure with function f1 described above, based on the corrected target amount of excavated soil. Average boom bottom pressure calculator 281 sends the average boom bottom pressure to average traction force calculator 282 and accelerator opening calculator 283. Since processing in average traction force calculator 282 and processing in accelerator opening calculator 283 have already been described, description will not be repeated. As set forth above, information on accelerator opening V2 is outputted from calculator 280A.
Correction processing in correction unit 284 will specifically be described as below.
In step S33, controller 10 (specifically, correction unit 284) calculates the value of x by inputting the value of the target amount of excavated soil calculated in step S32 into y in function f4 (x=αy2+βy+γ). In step S34, controller 10 (specifically, correction unit 284) sets the value of x as the target amount of excavated soil (corrected target amount of excavated soil).
Though x is set as the value of the target amount of excavated soil in generation of function f4, in correction, y is set as the value of the target amount of excavated soil as above. The target amount of excavated soil is inputted to y in function f4 like an inverse function. The corrected target amount of excavated soil is thus obtained as the value of x.
Description will be given below with reference to a simplified specific example. For example, it is assumed that three coordinate values (x1, y1), (x2, y2), and (x3, y3) are set to (4, 5), (6, 7.5), and (8, 10), respectively. Thus, it is assumed that soil is excavated 1.25 time as much as the target amount of excavated soil. In other words, the target amount of excavated soil is assumed as 0.8 time as large as the actually excavated amount of soil.
In this case, x=0.8y is obtained as function f4. When the target amount of excavated soil is 7.5 ton in the actual operation, 7.5 is substituted into y and 6 ton is obtained as the corrected target amount of excavated soil (x). By thus correcting (adjusting) the target amount of excavated soil from 7.5 ton to 6 ton, 7.5 ton of soil can consequently be scooped. By adjustment of the target amount of excavated soil inputted to calculator 280A, soil in the target amount of excavated soil inputted to calculator 280A can be excavated.
An application of present correction is not limited to an application to lowering in accuracy of calculator 280 due to change in quality of soil. Present correction can also be applied to lowering in accuracy of calculator 280 due to change of a method of controlling vehicular body 20. Typically, the amount of excavated soil is determined by the amount of penetration into the ground and the work implement speed. For example, in the case of control to vary the work implement speed with the vehicle speed, the amount of excavated soil may not accurately be controlled only by control of the accelerator opening (vehicle speed). Even in such a case, relation between the accelerator opening and the amount of excavated soil can be optimized by present correction to enhance accuracy in amount of excavated soil. In other words, present correction can rectify lowering in accuracy of calculator 280 due to change of the method of controlling vehicular body 20.
As set forth above, wheel loader 1 includes payload meter 99 that detects the weight of excavation target 100 loaded in bucket 6. Controller 10 includes correction unit 284 that corrects the target amount of excavated soil based on a difference between the target amount of excavated soil and the weight detected by payload meter 99. Calculator 280A calculates the accelerator opening based on the corrected target amount of excavated soil. Control in accordance with quality of soil of excavation target 100 can thus be achieved.
(2) Though the hydraulic mechanical transmission (HMT) wheel loader utilizing electronic control is described above by way of example of wheel loader 1, limitation thereto is not intended. Since the amount of excavated soil can be controlled based on the accelerator opening (vehicle speed) also in a wheel loader of a torque converter type, automatic control described above is applicable also to the wheel loader of the torque converter type, which will be described in detail below.
In the wheel loader of the torque converter type, when the target amount of excavated soil is small, the accelerator opening (vehicle speed) is decreased to decrease the amount of penetration into the ground. Though the work implement speed is preferably high in order to realize the small amount of excavated soil, the wheel loader of the torque converter type is incapable of such control. An effect of decrease in amount of penetration into the ground, however, is larger than an effect of lowering in work implement speed owing to lowering in vehicle speed (accelerator opening), and hence the wheel loader of the torque converter type can also adjust the amount of excavated soil.
Furthermore, correction in consideration of the effect of lowering in work implement speed owing to lowering in vehicle speed (accelerator opening) can further improve accuracy in amount of excavated soil. Present correction can be made with a method similar to rectification of lowering in accuracy of calculator 280 due to change of the method of controlling vehicular body 20.
By thus controlling the accelerator opening, the amount of excavated soil can be controlled. Furthermore, even when the operation of work implement 3 remains the same, so long as the amount of penetration into the ground can be adjusted at the time of change in accelerator opening (relation between the accelerator opening and the amount of soil that can be excavated can be corrected), accuracy in amount of excavated soil can further be improved.
(3) The configuration of automatic control of the work implement operation and the accelerator operation only while accelerator operation member 81a is being operated is described above. Specifically, for example, the configuration in which controller 10 starts automatic control of the work implement operation and the accelerator operation based on sensing of start of the excavation work while accelerator operation member 81a is being operated as shown in steps S5 to S7 in
(4) The load target is not limited to the dump truck. The load target is not limited to the self-propelled vehicle. For example, the load target may be a towed vehicle. In the soil ejection step, excavation target 100 may simply be ejected to a prescribed location.
(5) The configuration in which the target posture is calculated by using trained model 180 which is artificial intelligence is described above. So long as the amount of penetration into the ground can be adjusted by accelerator control in certain determined work implement control (position control, load control, or the like), however, artificial intelligence does not necessarily have to be used for calculation of the target posture.
Controller 10 may calculate the target posture with a calculation logic (arithmetic logic) prepared in advance. For example, controller 10 may determine the target posture based on a load applied to work implement 3. Controller 10 may control work implement 3 in accordance with the target posture determined in advance, in response to variation in boom cylinder pressure varied by repulsive force from the ground. Specifically, amount of change Δθ1 per unit time in boom angle θ1 with the boom cylinder pressure, as well as amount of change Δθ2 per unit time in bell crank angle θ2 and an amount of operation onto the boom may be stored in memory 10M, and controller 10 may control work implement 3 based on amounts of change θ1 and θ2.
The method of sensing a load applied to work implement 3 is not limited to sensing of the boom cylinder pressure. For example, a strain sensor or a torque sensor may be provided in work implement 3, the sensor may sense the load applied to work implement 3 by the ground, and controller 10 may control work implement 3 based on a result of sensing.
(6) In calculation of the target posture by using trained model 180 as described above, controller 10 has started calculation of the target posture before start of the excavation work, and it simply uses start of the excavation work as a trigger to control to the target posture of work implement 3. Therefore, it does not matter whether sensing of start of the excavation work or start of calculation of the target posture is earlier. In other words, controller 10 may initially calculate the target posture, and thereafter it may sense start of the excavation work and then control vehicular body 20 to be in the target posture. In contrast, controller 10 may calculate the target posture after it senses start of the excavation work, and then controller 10 may control vehicular body 20 to be in the target posture. When the calculation logic described above is used instead of trained model 180 as well, it does not matter whether sensing of start of the excavation work or start of the calculation of the target posture is earlier.
(7) Though controller 10 is configured to carry out the entirety of control in the above, an external controller may carry out a part or the entirety of control. For example, during automatic excavation, the external controller such as an edge terminal may send an operation voltage (operation signal) and controller 10 may receive the operation signal so that wheel loader 1 is operated. During works other than automatic excavation, the external controller (not shown) may constantly read a value detected by a sensor that reads a voltage value in a lever operation and the signal indicating the value may be provided to controller 10 so that wheel loader 1 is operated.
For example, by incorporating a logic for automatic excavation into controller 10 embedded in vehicular body 20, wheel loader 1 may be controlled without being provided with a signal from the external controller. Alternatively, the present technique may be applied also by transmission by the external controller, of a signal that directly causes a valve to be opened and closed without controller 10 being interposed.
The embodiment disclosed herein is illustrative and is not restricted only to the above contents. The scope of the present invention is defined by the terms of the claims and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
1 wheel loader; 2 vehicular body frame; 2a front frame; 2b rear frame; 2b frame; 2ton, 6ton target amount of excavated soil; 3 work implement; 4 traveling apparatus; 4a front wheel; 4a wheel; 5 cab; 6 bucket; 6a cutting edge; 6b rear surface; 8 operation apparatus; 9 boom pin; 10 controller; 10M memory; 11 steering cylinder; 13 work implement pump; 14 boom; 15 link; 16 boom cylinder; 17 bucket pin; 18 bell crank; 18a support pin; 18b, 18c coupling pin; 19 bucket cylinder; 20 vehicular body; 21 engine; 23 transmission; 27 input shaft; 28 output shaft; 29 first angel detector; 32 axle; 33 motive power extraction unit; 34 work implement valve; 48 second angle detector; 50 display; 51 operation key; 81a accelerator operation member; 81b accelerator operation detection unit; 83a boom operation member; 83b boom operation detection unit; 84a bucket operation member; 84b bucket operation detection unit; 85b shift change operation detection unit; 91 engine rotation speed sensor; 92 output rotation speed sensor; 95 first hydraulic pressure detector; 96 second hydraulic pressure detector; 99 payload meter; 100 excavation target; 150, 280, 280A calculator; 170 obtaining unit; 180 trained model; 181 input layer; 182 intermediate layer; 183 output layer; 231 planetary gear mechanism; 232, 233 hydraulic motor; 281 average boom bottom pressure calculator; 282 average traction force calculator; 283 accelerator opening calculator; 284 correction unit; H horizontal line; L, La, Lb bucket trace; P boom reference line; Q bell crank reference line.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-059934 | Mar 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/002552 | 1/27/2023 | WO |
