Patent Application
20230358019
This disclosure relates generally to a machine having an implement, and more particularly to systems and methods of controlling the position and/or movement of the implement.
Earth moving machines, such as, e.g., tractors, bulldozers, excavators, and material handlers may be equipped with work implements to perform various functions. For example, a tractor may be equipped with a work implement in the form of a blade for contouring or leveling a ground surface during construction. The position and movement of the work implement may be controlled by an operator and/or a controller. During operation, the machine may traverse uneven and/or changing terrain, causing the machine to pitch forward and/or aft and/or roll side to side. The operator and/or controller may compensate for change in pitch of the machine to maintain a desired implement position or movement path.
One method for compensating for changes in pitch of the machine includes operators manually adjusting the motion and position of the implement. However, skilled operators may have difficulty anticipating movement of the implement in response to uneven or varied terrain. As a result, operators may undercorrect or overcorrect the position and/or movement of the implement. Some machines include a control system to adjust the position and movement of the implement based on a variety of inputs. Such control systems may attempt to adjust for instantaneous changes in the pitch of the machine or implement, but such control systems may not adequately address these situations.
U.S. Pat. No. 9,328,479 to Rausch et. al. (“the '479 patent”) discloses a grade control system for controlling a ground-engaging blade of a machine. The system includes a controller that is configured to receive machine chassis and blade inclination signals, determine a target grade, determine a distance error based on the signals indicative of a distance between the blade and the target grade, and send a command to move the blade toward the target grade based on the distance error. However, the control system of the '479 patent may not sufficiently control and/or stabilize the blade during all modes and/or operating conditions of the machine.
Aspects of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the disclosure, however, is not defined by the ability to solve any specific problem.
According to one aspect of the present disclosure, a control system for a machine may include a chassis, an implement attached to the chassis, at least one sensor coupled to the chassis or the implement, and a controller in communication with the sensor. The controller may be configured to receive one or more signals from the at least one sensor, determine a stabilization factor based on the one or more signals from the at least one sensor, and signal one or more actuators to control a movement and/or a position of the implement based at least in part on the stabilization factor.
In another aspect, a method of controlling an implement of a machine may include receiving at a controller one or more signals indicative of one or more operating parameters of the machine, analyzing and/or integrating the one or more signals to determine a stabilization factor, and controlling one or more portions of the machine to move or change a position of the implement based on the one or more signals and the determined stabilization factor.
In yet another aspect, a control system for a machine may include a chassis, an implement attached to the chassis, at least one first sensor coupled to the chassis or the implement, at least one second sensor coupled to the chassis or the implement, and a controller in communication with the at least one first sensor and the at least one second sensor. The controller may be configured to receive one or more signals from the at least one first sensor at an integrator, determine an intermediate stabilization factor based on the one or more signals from the at least one first sensor, receive one or more signals from the at least one second sensor at a roading detection module to determine whether the machine is in a roading mode, and if the machine is not determined to be in a roading mode, signal one or more actuators to control a movement and/or a position of the implement based at least in part on the stabilization factor.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments, and together with the description serve to explain the principles of the disclosed embodiments.
Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, corresponding or similar reference numbers will be used, when possible, throughout the drawings to refer to the same or corresponding parts. Features in the drawings may not be drawn to scale, but may rather be drawn to highlight different aspects of the disclosure. In this disclosure, relative terms, such as, for example, “about,” “generally,” and “substantially” are used to indicate a possible variation of ±10% in a stated numeric value.
Although
Operation of machine 10 may be initiated by an operator in a cab 28 located on chassis 12. Cab 28 may include one or more operator controls 30, such as, e.g., one or more joysticks, touch screens, buttons, or switches. One or more operator controls 30 may send one or more signals to controller 26. For example, one or more of operator controls 30 may send an activation signal to activate one or more operating mode of controller 26. In one or more examples, one or more of operator controls 30 may signal controller 26 to activate one of the systems of controller 26, as described below. In another example, one or more of operator controls 30 may transmit a deactivation signal to controller 26 to deactivate a system of controller 26. Furthermore, in some examples, one or more aspects of controller 26 may be autonomous, semi-autonomous, and/or remotely controlled, for example, by an operator positioned remote from machine 10.
In some examples, operator controls 30 may be used for commanding movement and positioning of the blade 18. For example, operator controls 30 may be or otherwise include a joystick. In these aspects, moving the joystick forward may lower blade 18 (i.e., toward ground surface 2), and moving the joystick backward may raise blade 18 (i.e., away from ground surface 2). Movement of the joystick by the operator may transmit an operator command signal 52 to controller 26, as shown in
With reference to
Furthermore, machine 10 may be equipped with one or more inertial measurement units (IMUs). For example, machine 10 may include an IMU located on blade 18 (i.e., an implement IMU 34) and an IMU located on chassis 12 (i.e., a chassis IMU 36). One or more of the IMUs may include one or more accelerometers and one or more gyroscopes. Implement IMU 34 and/or chassis IMU 36 may measure acceleration in one or more dimensions or degrees of freedom. Based on acceleration measured by the IMU(s), the IMU(s) and/or controller 26 may determine velocity and/or position/orientation information associated with the IMU's position. The constant acceleration on each IMU due to gravity enables the IMUs to measure the position/orientation, velocity, and acceleration with respect to gravity, or an axis orthogonal to gravity. For example, implement IMU 34 may measure an angular position and angular velocity of blade 18 with respect to gravity. Similarly, chassis IMU 36 may measure an angular position and angular velocity of chassis 12 with respect to gravity. In these aspects, implement IMU 34 may help to determine an implement angle and/or an implement pitch, and chassis IMU 36 may help to determine a chassis angle and/or a chassis pitch. In some examples, each IMU and/or controller 26 may include a state estimator, such as, for example, a Kalman filter or a complimentary filter, to remove systematic errors from the IMU measurements including, but not limited to, sensor bias and non-gravitational acceleration. Implement IMU 34 may send an implement pitch signal 54 and/or an implement roll angle signal 62, indicative of an implement pitch and/or an implement roll angle, to controller 26. Chassis IMU 36 may send a chassis pitch signal 56 and/or a chassis roll angle signal 64, indicative of a chassis pitch and/or a chassis roll angle, to controller 26.
Furthermore, machine 10 may include one or more additional sensors, for example, coupled to one or more portions of machine 10 and communicably coupled to controller 26. For example, as shown in
Machine 10 may include a track speed sensor 40, for example, on or adjacent to one or more of tracks 16, for example, on or adjacent to a drive wheel 24, one or more idlers, or one or more other portions or components of one or more tracks 16. Although not shown, if machine 10 includes one or more wheels, machine 10 may include a wheel speed sensor. Track speed sensor 40 may be used to determine (e.g., either directly or indirectly) the speed of one or more of tracks 16. Track speed sensor 40 may send one or more track speed signals 61, indicative of a speed of one or more tracks 16, to controller 26.
Machine 10 may include a pitch noise sensor 42, for example, on or adjacent to blade 18. Pitch noise sensor 42 may be used to determine one or more noise levels, for example, based on the movement of blade 18. Pitch noise sensor 42 may be coupled to one or more IMUs, for example, on blade 18 and/or machine 10. Pitch noise sensor 42 may send one or more pitch noise signals 63, indicative of a pitch noise of blade 18, to controller 26. Pitch noise sensor 42 may include a dynamic filter factor, for example, measuring and/or detecting changes in the operator joystick signal (i.e., a blade raise command or a blade lower command). In some aspects, pitch noise sensor 42 may measure and/or detect vibrational and/or electrical noise, which may lead to error in the measurement of the machine pitch. In these aspects, the machine pitch may be the angle at which machine 10 is cutting (e.g., up or down) relative to gravity. Additionally, in some aspects, pitch noise may increase when machine 10 is traveling faster across ground surface 2, and pitch noise may decrease when machine 10 is traveling slower across ground surface 2.
In one or more aspects, operator control(s) 30 may also include a user interface, for example, to receive one or more user inputs indicative of one or more material properties of ground surface 2 and/or other operating parameters. Additionally, the user interface may display one or more indications, for example, based on information received from one or more of the sensors.
As shown in
Before proceeding further, it may be beneficial to define certain measurements and terms characterizing the operation of machine 10 and/or blade 18, as illustrated in
Controller 26 may be in communication with one or more features or portions of machine 10, for example, forming control system 100. As shown in
Although not shown, controller 26 may be coupled to or include one or more memory units, which may contain instructions for controller 26 to help control a position or movement of blade 18. Controller 26 may be a separate controller on machine 10, or may be integrated into a central vehicle controller (e.g., a main power controller, an operation controller, etc.). Alternatively, controller 26 may be integrated into one or more of control or management systems or modules (e.g., for operating engine 14) of machine 10, or another dedicated control module on machine 10. In one aspect, machine 10 may be an electrohydraulic dozer, and controller 26 may control one or more electrical switches or valves in order to control one or more hydraulic cylinders or electrical elements in order to operate machine 10.
Controller 26 may include one or more microprocessors. For example, controller 26 may embody a single microprocessor or multiple microprocessors. The one or more microprocessors of controller 26 may be configured to perform any of the operations mentioned herein. For example, controller 26 may include a memory, a secondary storage device, a processor, such as a central processing unit or any other means for accomplishing a task consistent with the present disclosure. The memory or secondary storage device associated with controller 26 may be non-transitory computer-readable media that store data and/or software routines that may assist controller 26 in performing its functions, such as the functions of process or method 400 of
With continued reference to
Stabilization factor system 102 may include a variable or adaptive stabilization factor 104, for example, to be provided to blade 18 (e.g., via hydraulic actuator 22). For example, the level of stabilization of blade 18 signaled by stabilization factor system 102 may depend on one or more of operator inputs on operator control 30 (e.g., a joystick), operator setting selections, machine motion, ground surface properties, and/or one or more other inputs or signals. For example, controller 26 (i.e., stabilization factor system 102) may deduce or otherwise calculate an operator intent based on one or more of the aforementioned inputs or signals. Additionally, controller (i.e., stabilization factor system 102) may modify the level of stabilization (e.g., a “filter factor”) based on the deduced or calculated operator intent.
In one example, stabilization factor 104 may adjust the threshold(s), range(s), etc. used to determine whether a fluctuation of implement mainfall angle ΘM is a low frequency fluctuation or a high frequency fluctuation. For example, as discussed in detail below, stabilization factor system 102 may include an integrator module 106. Integrator module 106 may help to control the amount or degree to which the position or movement of blade 18 is stabilized as machine 10 moves across ground surface 2. In one aspect, stabilization factor system 102 of controller 26 may include a roading detection module 108. In this aspect, integrator module 106 may be in communication (e.g., send signals) to roading detection module 108, which may also adjust stabilization factor 104.
As shown in
Integrator module 106 may receive signals from one or more of sensors. For example, integrator module 106 may receive operator command signal 52, for example, via operator control(s) 30, indicative of an operator's intended blade movement. In one example, operator controls module 106A may receive operator command signal 52. If operator command signal 52 is above a first threshold value, then operator controls module 106A of integrator module 106 may increase a stabilization value. If operator command signal 52 is below a second threshold value, then operator controls module 106A of integrator module 106 may decrease the stabilization value. Furthermore, if operator command signal 52 is in a certain range, for example, between the first threshold value and the second threshold value, then operator controls module 106A of integrator module 106 may not adjust the stabilization value. In these aspects, if operator command signal 52 is more than approximately 10% of a maximum operator command signal, then operator controls module 106A of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if operator command signal 52 is approximately 0% of the maximum operator command signal, then operator controls module 106A of integrator module 106 may decrease the stabilization value, for example, by 1. If operator command signal 52 is between approximately 10% and approximately 0% of the maximum operator command signal, then operator controls module 106A of integrator module 106 may not increase or decrease the stabilization value.
Furthermore, integrator module 106 may receive implement pitch signal 54, for example, via implement IMU 34. For example, implement IMU module 106B may receive implement pitch signal 54. If implement pitch signal 54 is above a first threshold value, then implement IMU module 106B of integrator module 106 may increase a stabilization value. If implement pitch signal 54 is below a second threshold value, then implement IMU module 106B of integrator module 106 may decrease the stabilization value. Furthermore, if implement pitch signal 54 is in a certain range, for example, between the first threshold value and the second threshold value, then implement IMU module 106B of integrator module 106 may not adjust the stabilization value. In these aspects, implement IMU module 106B of integrator module 106 may compare a received implement pitch signal 54 to a previously received implement pitch signal 54, for example, to determine a rate of change between sequential implement pitch signals 54. If the rate of change between sequential implement pitch signals 54 is greater than 0.5, then implement IMU module 106B of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if the rate of change between sequential implement pitch signals 54 is less than −0.5, then implement IMU module 106B of integrator module 106 may decrease the stabilization value, for example, by 1. If the rate of change between sequential implement pitch signals 54 is between 0.5 and −0.5, then implement IMU module 106B of integrator module 106 may not increase or decrease the stabilization value.
Alternatively or additionally, integrator module 106 may receive implement roll angle signal 62, for example, via implement IMU 34. For example, implement IMU module 106B may receive implement roll angle signal 62. If implement roll angle signal 62 is above a first threshold value, then implement IMU module 106B of integrator module 106 may increase a stabilization value. If implement roll angle signal 62 is below a second threshold value, then implement IMU module 106B of integrator module 106 may decrease the stabilization value. Furthermore, if implement roll angle signal 62 is in a certain range, for example, between the first threshold value and the second threshold value, then implement IMU module 106B of integrator module 106 may not adjust the stabilization value. In these aspects, implement IMU module 106B of integrator module 106 may compare a received implement roll angle signal 62 to a previously received implement roll angle signal 62, for example, to determine a rate of change between sequential implement roll angle signal 62. If the rate of change between sequential implement roll angle signal 62 is greater than 0.5, then implement IMU module 106B of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if the rate of change between sequential implement roll angle signal 62 is less than −0.5, then implement IMU module 106B of integrator module 106 may decrease the stabilization value, for example, by 1. If the rate of change between sequential implement roll angle signal 62 is between 0.5 and −0.5, then implement IMU module 106B of integrator module 106 may not increase or decrease the stabilization value.
Integrator module 106 may receive chassis pitch angle signal 56, for example, via chassis IMU 36. In some aspects, chassis pitch angle signal 56 may be a pitch angle difference, for example, between a pitch of chassis 12 and a pitch of blade 18. For example, chassis IMU module 106C may receive chassis pitch angle signal 56. If chassis pitch angle signal 56 is above a first threshold value, then chassis IMU module 106 of integrator module 106 may increase a stabilization value. If chassis pitch angle signal 56 is below a second threshold value, then chassis IMU module 106 of integrator module 106 may decrease the stabilization value. Furthermore, if chassis pitch angle signal 56 is in a certain range, for example, between the first threshold value and the second threshold value, then chassis IMU module 106 of integrator module 106 may not adjust the stabilization value. In these aspects, if chassis pitch angle signal 56 is more than approximately 5 degrees (e.g., greater than 5 degrees or less than −5 degrees), more than approximately 8 degrees (e.g., greater than 5 degrees or less than −8 degrees) or more than approximately 10 degrees (e.g., greater than 10 degrees or less than −10 degrees), then chassis IMU module 106 of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if chassis pitch angle signal 56 is approximately 0 degrees, then chassis IMU module 106 of integrator module 106 may decrease the stabilization value, for example, by 1. If chassis pitch angle signal 56 is between approximately 5 degrees and approximately −5 degrees, between approximately 8 degrees and approximately −8 degrees, or between approximately 10 degrees and approximately −10 degrees, then integrator module 106 may not increase or decrease the stabilization value.
Integrator module 106 may receive chassis roll angle signal 64, for example, via chassis IMU 36. In some aspects, chassis roll angle signal 64 may be a roll angle difference, for example, between a roll of chassis 12 and a roll of blade 18. For example, chassis IMU module 106C may receive chassis roll angle signal 64. If chassis roll angle signal 64 is above a first threshold value, then chassis IMU module 106C of integrator module 106 may increase a stabilization value. If chassis roll angle signal 64 is below a second threshold value, then chassis IMU module 106C of integrator module 106 may decrease the stabilization value. Furthermore, if chassis roll angle signal 64 is in a certain range, for example, between the first threshold value and the second threshold value, then chassis IMU module 106C of integrator module 106 may not adjust the stabilization value. In these aspects, if chassis roll angle signal 64 is more than approximately 5 degrees (e.g., greater than 5 degrees or less than −5 degrees), more than approximately 8 degrees (e.g., greater than 8 degrees or less than −8 degrees), or more than approximately 10 degrees (e.g., greater than 10 degrees or less than −10 degrees), then chassis IMU module 106C of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if chassis roll angle signal 64 is approximately 0 degrees, then chassis IMU module 106C of integrator module 106 may decrease the stabilization value, for example, by 1. If chassis roll angle signal 64 is between approximately 5 degrees and approximately −5 degrees, between approximately 8 degrees and approximately −8 degrees, or between approximately 10 degrees and approximately −10 degrees, then chassis IMU module 106C of integrator module 106 may not increase or decrease the stabilization value.
Integrator module 106 may receive speed signal 58, for example, via speed sensor 32. For example, speed sensor module 106D may receive speed signal 58. If speed signal 58 is above a first threshold value, then speed sensor module 106D of integrator module 106 may increase a stabilization value. If speed signal 58 is below a second threshold value, then speed sensor module 106D of integrator module 106 may decrease the stabilization value. Furthermore, if speed signal 58 is in a certain range, for example, between the first threshold value and the second threshold value, then speed sensor module 106D of integrator module 106 may not adjust the stabilization value. In these aspects, if speed signal 58 is indicative of a machine speed that is more than approximately five miles per hour, then speed sensor module 106D of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if speed signal 58 is indicative of a machine speed that is less than 2 miles per hour, then speed sensor module 106D of integrator module 106 may decrease the stabilization value, for example, by 1. If speed signal 58 is between approximately 5 miles per hour and approximately 2 miles per hour, then speed sensor module 106D of integrator module 106 may not increase or decrease the stabilization value.
Moreover, integrator module 106 may receive ground surface signal 60, for example, via ground surface sensor 38. For example, ground surface sensor module 106E may receive ground surface signal 60. If ground surface signal 60 is above a first threshold value, for example, indicative of a first density, hardness, material, or other property of ground surface 2, then ground surface sensor module 106E of integrator module 106 may increase a stabilization value. If ground surface signal 60 is below a second threshold value, for example, indicative of a first density, hardness, material, or other property of ground surface 2, then ground surface sensor module 106E of integrator module 106 may decrease the stabilization value. Furthermore, if ground surface signal 60 is in a certain range, for example, between the first threshold value and the second threshold value, then ground surface sensor module 106E of integrator module 106 may not adjust the stabilization value. In these aspects, if ground surface signal 60 is indicative of a ground surface 2 that is denser, harder, rockier, etc., then ground surface sensor module 106E of integrator module 106 may increase the stabilization value, for example, by 1. Similarly, if ground surface signal 60 is indicative of a ground surface that is less dense, softer, less rocky (i.e., sandier), etc., then ground surface sensor module 106E of integrator module 106 may decrease the stabilization value, for example, by 1. If ground surface signal 60 is indicative of a moderate material property of ground surface 2, then ground surface sensor module 106E of integrator module 106 may not increase or decrease the stabilization value.
Additionally, in some aspects, integrator module 106 may receive one or more additional signals, for example, from one or more other sensors. Furthermore, in some aspects, integrator module 106 may receive one or more user inputs, for example, from a user interface in cab 28, remote from machine 10, or otherwise in communication with controller 26.
As mentioned, in some aspects, stabilization factor system 102 may include roading detection module 108. For example, integrator module 106 may receive signals from one or more of the aforementioned IMUS and/or sensors, and integrator module 106 may send an intermediate stabilization factor 107 to roading detection module 108. Roading detection module 108 may receive one or more signals from track speed sensor 40 and/or pitch noise sensor 42. For example, roading detection module 108 may receive track speed signal 61 from track speed sensor 40, and/or may receive pitch noise signal 63 from pitch noise sensor 42. Based on track speed signal 61 and/or pitch noise signal 62, roading detection module may determine whether machine 10 is in a roading state. For example, the roading state may correspond to machine 10 being driven to a new location on the worksite, being driven to a new worksite, being maneuvered on a road, or otherwise being operated without blade 18 in operation. In these examples, blade 18 not being in operation may correspond to blade 18 being raised away or elevated from ground surface 2 in order to not engage with ground surface 2, or otherwise in a position where machine 10 is not actively grading, shaping, or otherwise intentionally treating ground surface 2. If roading detection module 108 does not detect that machine 10 is in a roading mode, then roading detection module 108 allows intermediate stabilization factor 107 to pass through. In this aspect, roading detection module 108 sends stabilization factor 104 to an actuator to control blade 18, for example, to hydraulic actuator 22. If roading detection module 108 detects that machine 10 is in a roading state, roading detection module 108 modifies intermediate stabilization factor 107. For example, in one aspect, when roading detection module 108 detects that machine 10 is in the roading state, roading detection module 108 may maintain a previous stabilization factor (i.e., and not transmit intermediate stabilization factor 107). Alternatively, in another aspect, when roading detection module 108 detects that machine 10 is in the roading state, roading detection module 108 may reset the stabilization factor. Resetting the stabilization factor may include transmitting a baseline or standard stabilization factor as stabilization factor 104 to implement mainfall angle cutoff frequency module 118. Alternatively, resenting the stabilization factor may include reducing the stabilization factor 104 to zero, for example, such that blade 18 is not stabilized.
In these aspects, if track speed signal 61 is indicative of a roading speed, then roading detection module 108 may determine that machine 10 is in the roading mode. The roading speed may be, for example, greater than approximately 5 miles per hour, approximately 7 miles per hour, approximately 10 miles per hour, approximately 15 miles per hour, approximately 20 miles per hour, etc. Additionally or alternatively, if pitch noise signal 63 is indicative of a roading condition, then roading detection module 108 may determine that machine 10 is in the roading mode. In this aspect, the roading condition may be, for example, a signal indicative of pitch noise greater than approximately 5% of a maximum noise level, approximately 10% of the maximum noise level, approximately 15% of the maximum noise level, approximately 20% of the maximum noise level, approximately 25% of the maximum noise level, etc. In some aspects, roading detection module 108 may also receive signals indicative of and/or adjust one or more machine parameters based on one or more of electronic noise, mechanical vibrations, and/or one or more other characteristics that may contribute error to one or more measurements (e.g., machine pitch). Alternatively or additionally, roading detection module 108 may determine that machine 10 is in the roading mode and/or adjust stabilization factor 106 based on one or more of inputs on operator controls 30 (i.e., the joystick), a position of blade 18, for example, relative to machine chassis 12, the speed of tracks 16, the load of engine 14, pitch of machine chassis 12, etc. In these aspects, roading detection module 108 may detect roading when either track speed signal 61 or pitch noise signal 63 is above one or more thresholds. In another aspect, roading detection module 108 may only detect roading if both track speed signal 61 and pitch noise signal 63 are above respective thresholds.
In another aspect, instead of intermediate stabilization factor 107 being sent from integrator module 106 to roading detection module 108, roading detection module 108 may be integral with integrator module 106, and may override or otherwise adjust any signals to be emitted from integrator module 106 (e.g., to hydraulic actuator 22) when roading is detected. In this aspect, track speed sensor 40 and/or pitch noise 42 may send track speed signal 61 and/or pitch noise signal 63 to integrator module 106. Furthermore, although not shown, roading detection module 108 may include one or more separate modules, for example, a track speed sensor module to receive track speed signal 61 from track speed sensor 40 and/or a pitch noise sensor module to receive pitch noise signal 63 from pitch noise sensor 42.
Controller 26 may include one or more additional function modules and systems, such as, e.g., blade control system 150 to process and control the movement and position of blade 18. Blade control system 150 may maintain blade 18 at a relatively constant implement mainfall angle ΘM while accommodating for low frequency fluctuations of the implement mainfall angle ΘM resulting from machine 10 moving across ground surface 2. Blade control system 150 may adjust the position of blade 18 based only on the low frequency fluctuations by rejecting high frequency changes to the implement mainfall angle ΘM. Low frequency fluctuations of the implement mainfall angle ΘM may be caused by changes in the trends of the terrain along ground surface 2, such as, e.g., changes in the slope of ground surface 2. High frequency disturbances of the implement mainfall angle ΘM may be caused by short bumps or other irregularities along ground surface 2.
Blade control system 150 may include a module 114, for example, a chassis pitch angle module 114, to determine the chassis pitch angle 164 based on the chassis pitch signal 56. Blade control system 150 may include another module 112, for example, an implement angle module 112, to determine the implement angle 162 based on the implement pitch signal 54. Blade control system 150 may include a latch 120 configured to receive the operator command signal 52. Latch 120 may trigger based on the operator command signal 52. For example, transitioning operator control 30, e.g., a joystick, to the neutral position may send an operator command signal 52 to controller 26 that triggers latch 120. Once triggered, latch 120 may pass the current implement angle 162 through latch 120 to generate the last commanded implement angle 126. The last commanded implement angle 126 may be indicative of the implement angle 162 measured at the time operator control 30 (e.g., a joystick) transitions to the neutral position, for example, indicative of the most recently commanded implement angle. Another module 134, for example, a comparison module 134, may compare chassis pitch angle 164 with implement angle 162 to determine the implement mainfall angle ΘM. Comparison module 134 may transmit the implement mainfall angle ΘM to another module 138, for example, a difference angle module 138.
Controller 26 may include a low pass filter 122. Low pass filter 122 may be weighted or adjusted based on a machine speed 166 and/or implement mainfall angle cutoff frequency 68. Implement mainfall angle cutoff frequency module 118 may determine the implement mainfall angle cutoff frequency 68. The implement mainfall angle cutoff frequency 68 may be a static value stored in memory accessible by the controller 26. In at least some examples, however, implement mainfall angle cutoff frequency 68 may be adaptively determined based on perceived operator application of machine 10, e.g., fine grading applications may use a relatively low frequency and bulk earthmoving applications may use a relatively high frequency, and/or other sensed measurements. For example, as discussed above, implement mainfall angle cutoff frequency module 118 may receive stabilization factor 104, for example, from one or more of integrator module 104 and/or roading detection module 108. Stabilization factor 104 may either increase or decrease implement mainfall angle cutoff frequency 68, or stabilization factor 104 may not affect implement mainfall cutoff frequency 68. The implement mainfall angle cutoff frequency 68 may ensure that machine speed 166 is not used to adjust the low pass filter 122 if machine 10 is moving too slowly or too fast for low pass filter 122 to accurately filter the chassis pitch angle 164. Low pass filter 122 may be adjusted based on a weight factor, K1, determined at a module, for example, a weight factor module 124. Weight factor module 124 may compare machine speed 166 and implement mainfall angle cutoff frequency 68. Low pass filter 122 may filter the chassis pitch angle 164 to determine a filtered chassis pitch angle 128. By utilizing low pass filter 122, filtered chassis pitch angle 128 may be determined in part based on the change in the chassis pitch angle 164 over time, along with stabilization factor 104 received from stabilization factor system 102, as discussed above.
Blade control system 150 may include another module 130, for example, a target mainfall angle module 130, which may compare the last commanded implement angle 126 to filtered chassis pitch angle 128 to determine a target implement mainfall angle 132. The implement mainfall angle ΘM may be compared to the target implement mainfall angle 132 at difference angle module 138 to determine a difference angle 140. At another module 142, for example, a command signal module 142, controller 26 may generate command signal 50 for directing movement of blade 18 based on difference angle 140. In some examples, command signal module 142 may correspond to a distinct controller, e.g., a PID controller. Command signal 50 may initiate movement of blade 18 to the target implement mainfall angle 132, e.g., by actuating one or more of hydraulic actuator(s) 22.
Method 400 includes an initial step 402, which includes initiating or beginning a machine operation. For example, step 402 may include powering up or otherwise starting machine 10 and operating machine 10. Operating machine 10 may include powering engine 14, manipulating blade 18, and/or activating one or more of hydraulic actuator 22, control system 100, a navigation system, an illumination system, or other aspects of machine 10. Step 402 may include an operator action, for example, starting machine 10 and/or directing machine 10 to perform an operation (e.g., a grading or earth moving operation).
Next, method 400 includes a step 404, which includes automatically adjusting a stabilization factor and controlling a position (or movement) of an implement. As discussed above, control system 100 may include operator control(s) 30 and a plurality of sensors. Controller 26, for example, stabilization factor system 102, may receive one or more signals from operator control(s) 30 and/or one or more of the plurality of sensors. Stabilization factor system 102 includes integrator module 106, which analyzes and integrates or otherwise combines the received signals to output or generate intermediate stabilization factor 107. In some aspects, intermediate stabilization factor 107 may pass through roading detection module 108, and stabilization factor 104 may be sent to implement mainfall angle cutoff frequency module 118 (
Method 400 then includes a step 406, which includes continuing the operation and continuously adjusting the stabilization factor and controlling the position of the implement. As discussed herein, operator control(s) 30 and/or one or more of the plurality of sensors may continuously or periodically send one or more signals to stabilization factor system 102 (i.e., to integrator module 106). In this aspect, integrator module 106 may continuously adjust stabilization factor 104, which may then be implemented by hydraulic actuator 22 and/or one or more other aspects of machine 10 discussed herein, in order to control the position and/or movement of blade 18 throughout the course of the operation.
In some aspects, method 400 includes a step 408, which includes a determination of whether roading is detected. As discussed above, stabilization factor system 102 may include roading detection module 108. Roading detection module 108 may receive intermediate stabilization factor 107 from integrator module 106. Additionally, roading detection module 108 may receive one or more signals from one or more sensors, for example, track speed sensor 40 and/or pitch noise sensor 42. If roading detection module 108 does not detect roading, then method 400 may return to step 406. However, if roading detection module 108 detects roading (e.g., based on a received track speed signal 61 and/or a received pitch noise signal 63), then method 400 may proceed to step 410. In these aspects, when detecting roading, roading detection module 108 may maintain, reset, or otherwise adjust intermediate stabilization factor 107 before sending the adjusted stabilization factor 104 to hydraulic actuator 22 and/or one or more other aspects of machine 10 discussed herein. For example, step 410 may include disabling the automatic adjustment of the stabilization factor and the control of the position of the implement. In some aspects, if roading detection module 108 no longer detects roading, then method 400 may also then return to step 406.
The present disclosure may be applicable in systems and methods for controlling an implement on a machine, such as, e.g., blade 18 on machine 10. During operation, movement of machine 10 across uneven terrain of ground surface 2 may cause chassis 12 and/or blade 18 to pitch forward and aft, roll side-to-side, or otherwise move, which may affect the position and/or movement of blade 18. The position and/or movement of blade 18 may affect the grade cut into ground surface 2 by blade 18. Stabilization factor system 102 and/or other aspects of control system 100, as discussed herein, may help to control and/or augment position and/or movement of blade 18. For example, stabilization factor system 102 and/or other aspects of control system 100 may help to adjust the implement mainfall angle ΘM and/or refine instructed movement of blade 18. Accordingly, stabilization factor system 102 and/or other aspects of control system 100 may help to produce a smooth grading profile of ground surface 2 by augmenting and/or adjusting the implement mainfall angle ΘM or operator commands to compensate for unintentional changes in the pitch, angle, speed, etc. of machine 10, chassis 12, and/or blade 18.
Furthermore, stabilization factor system 102 may provide an adjustably filter factor or stabilization factor 104. Stabilization factor 104 may be provided to implement mainfall angle cutoff frequency module 118, applied to one or more inputs (i.e., operator inputs on operator control(s) 30), sensed measurements (i.e., by any one or more of the sensors discussed herein), and/or output commands or signals (i.e., signals to hydraulic actuator 22 to control the movement and/or position of blade 18). For example, stabilization factor 104 may either increase or decrease implement mainfall angle cutoff frequency 68, or stabilization factor 104 may not affect implement mainfall cutoff frequency 68. Alternatively or additionally, stabilization factor 104 may be provided to weight factor module 124, for example, which may adjust the weight factor K1 and/or another adjustment of one or more sensed measurements. In these aspects, control system 100 may help machine 10 to accommodate and/or account for changes in operator commands, implement movement and/or position, chassis movement and/or position, machine speed, and/or ground surface parameters. In these aspects, control system 100 may help to maintain blade 18 in a highly stable position relative to ground surface 2 when machine 10 is operating on a flat surface. Moreover, control system 100 may also help to move and/or adjust the position of blade 18 when machine 10 is operating on a bumpy, sloped, or otherwise unstable terrain. Furthermore, control system 100 may allow for the adjustment of the movement and/or position of blade 18 to be done with minimal user input.
Furthermore, stabilization factor system 102, for example, via roading detection module 108, may help machine 10 to detect when stabilization of implement 18 is not necessary, for example, when blade 18 is not engaged with and/or is elevated from ground surface 2 and/or when machine 10 is in a roading mode. As discussed, roading detection module 108 may receive one or more signals from, for example, track speed sensor 40 and/or pitch noise sensor 42. In these aspects, when track speed signal 61 indicates a certain speed and/or when pitch noise signal 63 indicates that blade 18 is not engaged with and/or is elevated from ground surface 2, roading detection module 108 may maintain, reset, or otherwise adjust intermediate stabilization factor 107 before sending the adjusted stabilization factor 104 to hydraulic actuator 22 and/or one or more other aspects of machine 10 discussed herein. For example, roading detection module 108 may help to temporarily reduce the operation level of control system 100 and/or reduce the movements and/or positioning applied to blade 18 when machine 10 is in a roading mode. Additionally, roading detection module 108 may allow for the roading detection to occur automatically, that is, without an operator manually activating stabilization (i.e., in steps 304 and 306) or deactivating stabilization (i.e., in step 410).
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system without departing from the scope of the disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It may be intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
