Patent Application
20250034836
The present disclosure generally relates to mobile construction equipment, such as a motor grader, and more particularly to methods and controllers for managing the ability of a surface-engaging work tool of the mobile construction equipment, such as a blade of a motor grader, to float with respect to the surface on which the mobile construction equipment is operating.
Mobile construction equipment can be used for road work, ditch work, site preparation, and other surface contouring and finishing tasks. The versatility of mobile construction equipment is provided in large part by the ability to mount one or more surface-engaging work tools to the mobile construction equipment.
As shown, motor grader 10 includes a front frame 12 and rear frame 14. Rear frame 14 includes a power source, contained within a rear compartment 20, that is operatively coupled through a transmission to rear traction devices or wheels 22 for primary machine propulsion. The power source may be, for example, a diesel engine, a gasoline engine, a natural gas engine, or any other engine. The power source may also be an electric motor linked to a fuel cell, capacitive storage device, battery, or another source of power. Rear wheels 22 are operatively supported on tandem axles 24, which are pivotally connected to motor grader 10 between rear wheels 22 on each side of motor grader 10. The transmission may be a mechanical transmission, hydraulic transmission, or any other transmission type. The transmission may be operable to produce multiple output speed ratios (or a continuously variable speed ratio) between the power source and driven traction devices.
Motor grader 10 includes an articulation joint 62 that pivotally connects front frame 12 and rear frame 14. Both a left articulation actuator 64 and right articulation actuator 66 are connected between front frame 12 and rear frame 14 on opposing sides of motor grader 10, as shown in
Front frame 12 typically supports an operator station 26 that contains operator controls, along with a variety of displays or indicators, such as user interface 27, for conveying information to the operator for primary operation of motor grader 10, or receiving input from the operator. For example, motor grader 10 may include a machine speed sensor 90, which could be any sensor configured to monitor machine speed V, including sensors associated with any of the front wheels 58, 60, rear wheels 22, axle shafts, motors, or other components of the drivetrain of motor grader 10. Machine speed V could be displayed on user interface 27. Operator station 26 may also include one or more steering controls 106 (e.g., for steering front wheels 58, 60). Steering controls 106 may be, for example, a steering wheel 106 or any other type of operator input device, such as a dial, joystick, keyboard, pedal, or other devices. Operator station 26 also includes one or more articulation controls 116 (e.g., for controlling left and right articulation actuators 64, 66). Articulation controls 116 could also be any type of operator input device, such as a dial, joystick, keyboard, pedal, or other device.
Beam 28 of front frame 12 may support a surface-engaging work tool, such as main blade assembly 16, which moves blade 30 thereof to a wide range of positions relative to motor grader 10 and surface 86. Blade 30 is but one example of a surface-engaging work tool. Other surface-engaging work tools can include a front blade assembly with its own blade, rippers, snow wings, scarifiers, buckets, etc., and the discussion herein of blade 30 is equally applicable to all other types of surface-engaging work tools.
Main blade assembly 16 includes a drawbar 32 pivotally mounted to a first end 34 of beam 28 via a ball joint or the like. The position of drawbar 32 is typically controlled by hydraulic cylinders: right lift cylinder 36 and left lift cylinder 38, as shown in
Drawbar 32 may include a large, flat plate, commonly referred to as a yoke plate 42. Beneath yoke plate 42 is a circular gear arrangement and mount, commonly referred to as a circle 44. Circle 44 is rotated by, for example, a hydraulic motor known as a circle drive 46. Rotation of circle 44 by circle drive 46 rotates attached blade 30 about a circle axis A perpendicular to a plane of yoke plate 42.
Blade 30 is also mounted to circle 44 via a pivot assembly 50 that allows for tilting of blade 30 relative to circle 44. A blade tip cylinder 52 is used to tilt blade 30 forward or rearward. In other words, blade tip cylinder 52 is used to tip or tilt a top edge 54 of blade 30 relative to a bottom cutting edge 56 of blade 30, which is commonly referred to as blade tip. Blade 30 is also mounted to a sliding joint associated with circle 44 that allows blade 30 to slide or shift from side-to-side relative to circle 44. The side-to-side shift is commonly referred to as blade side shift. A side shift cylinder or the like is used to control the blade side shift.
The foregoing components allow for movement of blade 30 in a number of different manners. To determine a position of blade 30, motor grader 10 can include, for example, mainfall sensor 136, rotation sensor 138, and blade slope sensor 140, as shown in
Mainfall sensor 136 may be a single multi-axis inertial measurement unit (“IMU”) configured to produce a signal indicative of the longitudinal pitch of motor grader 10 and a signal indicative of the lateral roll of motor grader 10. IMUs are self-contained sensor systems capable of generating signals indicative of linear and angular motion. A multi-axis IMU includes two or more gyroscopes and accelerometers for measuring linear and angular motion in at least two dimensions (e.g., along two axes). The axes of the multi-axis IMU are typically aligned with the longitudinal axis of motor grader 10 and the lateral axis of motor grader 10 to generate signals indicative of the longitudinal pitch and lateral roll of motor grader 10, respectively.
Rotation sensor 138 may be configured to produce a signal indicative of the angle of blade 30 relative to front frame 12 and the lateral axis of motor grader 10. Rotation sensor 138 produces a signal indicative of the direction of blade 30 relative to the direction of travel of motor grader 10.
Blade slope sensor 140 may be configured to produce a signal indicative of the lateral slope of blade 30. The axis of mainfall sensor 136 is aligned with the longitudinal axis of motor grader 10 to generate signals indicative of the longitudinal pitch of motor grader 10, while blade slope sensor 140 generates signals indicative of the lateral roll of motor grader 10 when blade 30 is aligned with a lateral axis of motor grader 10.
Rotation sensor 138 can be used in conjunction with blade slope sensor 140 to determine the lateral roll of motor grader 10 when blade 30 is aligned with the lateral axis of motor grader 10, ensuring that signals from blade slope sensor 140 are measuring the slope of a surface that is perpendicular to the direction of travel of motor grader 10.
As shown, control system 94 may incorporate a number of inputs related to a position of a surface-engaging work tool, such as inputs from mainfall sensor 136, rotation sensor 138, blade slope sensor 140, machine speed sensor 90, and user interface 27, among others, in order to control an output related to the surface-engaging work tool, such as a position of blade 30 (e.g., by actuating one or more of right and left lift cylinder 36, 38, center shift cylinder 40, circle drive 46, blade tip cylinder 52, etc.).
Although
In certain situations, it is desirable for a surface-engaging work tool, such as blade 30, to “float” with respect to surface 86, as shown in
Although
In a non-float position PNF, as shown in
Although
When a surface-engaging work tool, such as blade 30, is floating with respect to surface 86 (i.e., as shown in
One aspect of the present disclosure is directed to a mobile construction equipment for operation on a surface, the mobile construction equipment comprising: a work tool that is movable between at least one float position, in which the work tool floats with respect to the surface, and at least one non-float position, in which the work tool does not float with respect to the surface; a machine speed sensor configured to provide a machine speed of the mobile construction equipment; and a controller having a work tool float mode, in which the work tool is movable to the at least one float position, the controller being configured, in a work tool float inhibit mode, in which the work tool is not movable to the at least one float position, to receive the machine speed, and, if the machine speed exceeds a float activation limit, at least one of: disable the work tool float mode so as to prevent the work tool from moving to the at least one float position, or provide an indication to an operator of the mobile construction equipment that the machine speed exceeds the float activation limit.
Another aspect of the present disclosure is directed to a method for transitioning a work tool of a mobile construction equipment between at least one float position, in which the work tool floats with respect to a surface on which the mobile construction equipment is operating, and at least one non-float position, in which the work tool does not float with respect to the surface, the mobile construction equipment having a controller, the method comprising: in a work tool float inhibit mode of the controller, in which the work tool is not movable to the at least one float position, receiving, by the controller, a machine speed of the mobile construction equipment; and if the machine speed does not exceed a float activation limit, enabling, by the controller, a work tool float mode, in which the work tool is movable to the at least one float position; or if the machine speed exceeds the float activation limit, at least one of: disabling, by the controller, the work tool float mode so as to prevent the work tool from moving to the at least one float position, or providing an indication to an operator of the mobile construction equipment that the machine speed exceeds the float activation limit.
A further aspect of the present disclosure is directed to a controller for a mobile construction equipment having a work tool movable between at least one float position, in which the work tool floats with respect to the surface, and at least one non-float position, in which the work tool does not float with respect to the surface, the controller being configured to: in a work tool float inhibit mode of the controller, in which the work tool is not movable to the at least one float position, receive a machine speed of the mobile construction equipment; and if the machine speed does not exceed a float activation limit, enable a work tool float mode, in which the work tool is movable to the at least one float position; or if the machine speed exceeds the float activation limit, at least one of: disable the work tool float mode so as to prevent the work tool from moving to the at least one float position, or provide an indication to an operator of the mobile construction equipment that the machine speed exceeds the float activation limit.
The present application describes methods and controllers for managing the ability of a surface-engaging work tool of a mobile construction equipment to float with respect to a surface on which the mobile construction equipment is operating.
Although the present application focuses on moving blade 30 of main blade assembly 16 between at least one float position PF and at least one non-float position PNF, the discussion herein is equally applicable to any and all other surface-engaging work tools beyond blade 30 of main blade assembly 16, including a front blade assembly with its own blade, rippers, snow wings, scarifiers, buckets, etc. Moreover, although the present application focuses on motor grader 10 as the mobile construction equipment, the discussion herein is equally applicable to any other mobile construction equipment to which a surface-engaging work tool can be mounted, including, for example, excavators, loaders, trucks, pavers, planers, compactors, shovels, material handlers, etc.
Turning to
If work tool float inhibit mode MI is activated, the method proceeds to step 702, wherein controller 96 compares machine speed V to float activation limit LFA. Machine speed V is inputted to controller 96 by machine speed sensor 90, while float activation limit LFA may be input to controller 96 at input 144. Float activation limit LFA is a machine speed above which it is unsafe to place blade 30 into float position PF, For example, above a certain machine speed, such as fifteen miles per hour, it may be deemed unsafe to put blade 30 into float position PF, as doing so may increase the likelihood of a negative consequence with respect to motor grader 10 if blade 30 contacts an impediment while in float position PF, Float activation limit LFA may be adjustable (e.g., by the operator of motor grader 10).
If machine speed V is greater than float activation limit LFA, the method proceeds to step 704, in which work tool float mode MF is disabled (i.e., via output 150) and/or controller 96 provides an indication I to the operator of motor grader 10 (i.e., output 154). When work tool float mode MF is disabled, blade can no longer be moved to float position PF. Such a situation is desirable if, as discussed previously, machine speed V is too high for blade 30 to float safely. Either alternatively or in addition to disabling work tool float mode MF, controller 96 can also in step 704 provide indication I, which may be, for example, a visual or audio warning that machine speed V is too high to safely operate blade 30 in float position Pr. In response to indication I, the operator of motor grader 10 can then manually lower machine speed V below float activation limit LFA if it is still desired to place blade 30 into float position PF.
If machine speed V is not greater than float activation limit LFA, the method proceeds to step 706, in which work tool float mode MF is enabled (i.e., via output 150). When work tool float mode MF is enabled, blade 30 is movable to float position PF. In other words, the method determines that machine speed V is low enough such that placing blade 30 into float position PF will not present an undue risk to the operator of motor grader 10 or to motor grader 10 itself.
Once controller 96 is placed into work tool float mode MF, controller 96 then determines, at step 708, whether it has received a float request R (via input 146). A float request R is a request that blade 30 be placed into float position PF, If controller 96 determines that float request R has been received, at step 710 controller 96 places blade 30 into float position PF, Blade 30 being in float position PF is equivalent to the float being “active,” as shown in
Furthermore, if the float is active, in step 712 controller 96 applies float active machine speed limit LFAMS (via output 152) so as to limit machine speed V to float active machine speed limit LFAMS while blade 30 is in float position PF. In particular, float active machine speed limit LFAMS is a maximum permissible machine speed V at which motor grader 10 can be operated while blade 30 is in float position PF. Float active machine speed limit LFAMS may be adjustable (e.g., by the operator of motor grader 10), and may be the same quantity or a different quantity than float activation limit LFA. For example, float active machine speed limit LFAMS and float activation limit LFA may need to be set at different values to avoid a sudden change in machine motion if the operator of motor grader 10 wishes to accelerate motor grader 10 while putting blade 30 into float position PF. Moreover, in a conventional transmission machine, float active machine speed limit LFAMS could be set at a value to prevent shifting the transmission into a higher gear so at to prevent motor grader 10 from attaining a higher machine speed V.
After applying float active machine speed limit LFAMS, controller 96 continues to evaluate, at step 708, whether float request R continues to be received. If float request R continues to be received, it is indicative of the operator of motor grader 10 wanting to keep blade 30 in float position PF, However, if float request R is no longer received, then the operator of motor grader 10 wants blade 30 to be moved from float position PF to non-float position PNF.
Alternatively, if after entering work tool float mode MF controller 96 determines, at step 708, that no float request R has been received (via input 146), the method proceeds to step 714, in which the float is inactive and blade 30 is maintained in non-float position PNF. When blade 30 is in non-float position PNF (either because no float request R was ever received after entering work tool float mode MF, or because a float request R was initially received but then withdrawn), there is generally no need to limit machine speed V for any reason relating to float. In step 716, the method therefore removes float active machine speed limit LFAMS so as to not limit machine speed V to float active machine speed limit LFAMS.
If the last two digits of the step numbers in
After work tool float inhibit mode MI is activated in step 800, controller 96 determines whether it receives work tool float inhibit override O at input 148. If work tool float inhibit override O at input 148 has not been received, the method in
In the case where controller 96 is in work tool float mode MF and a float request R has been received (i.e., in step 810), the method of
In general, the mobile construction equipment, methods, and controllers of the present application are applicable for limiting the ability of a surface-engaging work tool to be put into a float position and/or limiting a machine speed of a mobile construction equipment to which the work tool is attached when the work tool is in the float position. By limiting the mobile construction equipment in this manner, the present application describes techniques for safer operation of mobile construction equipment when floating a surface-engaging work tool, namely by not allowing the work tool to be moved into the float position when the mobile construction equipment is operating at a higher machine speed. Furthermore, through the work tool float inhibit mode itself, the present application describes techniques for disallowing the ability to float the work tool in specific situations, which can be helpful if the operator of the mobile construction equipment to which the work tool is attached is inexperienced. The present application also describes the ability to manually override the work tool float inhibit mode so as to allow the work tool to float irrespective of the machine speed.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
The present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
