SYSTEMS AND METHODS FOR CONTROLLING A MACHINE IMPLEMENT

A control system for a machine includes 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 is 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.

TECHNICAL FIELD

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.

BACKGROUND

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.

SUMMARY OF THE DISCLOSURE

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.

DETAILED DESCRIPTION

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.

FIG.1illustrates an exemplary machine10in the form of a tractor, including an implement, for example, a blade18. Machine10may include a chassis12and an engine14. Machine10may be a tractor, for example, a track-type tractor. For example, engine14may drive tracks16to propel machine10across a ground surface2. Blade18may be pivotably attached or connected to chassis12by an arm20, for example, at a pivot point X. Movement (e.g., rotation) of arm20may raise or lower blade18. At least one hydraulic actuator22may couple chassis12and blade18. For example, a right side of machine10may include a first hydraulic actuator22, and a left side of machine10may include a second hydraulic actuator (not shown). Actuating hydraulic actuator(s)22(e.g., by operating one or more valves and/or solenoids to extend or retract a rod22A relative to a cylinder22B) may move blade18relative to chassis12. For example, extending rod(s)22A of hydraulic actuator(s)22may lower the blade18, which may also rotate arm20(i.e., clockwise) about pivot point X. In another example, retracting rod(s)22A of hydraulic actuator(s)22may raise blade18, which may also rotate arm20(i.e., counterclockwise) about pivot point X. As discussed in detail below, in some aspects, machine10includes a controller26, which may be coupled to one or more sensors, control systems, actuators, etc., in order to help control the position of blade18relative to chassis12. Controller26may receive one or more inputs, and emit one or more outputs, for example, to help stabilize blade18. Furthermore, controller26may adjust a level of stabilization based on the one or more inputs and/or other sensed characteristics of machine10, ground surface2, etc.

AlthoughFIG.1illustrates machine10being a tractor having a blade18, this is exemplary and this disclosure is not so limited. For example, the present disclosure may be applicable to other work machines (e.g., loaders, excavators, etc.) having other types of implements (e.g., augers, forks, buckets, hammers, plows, rippers, etc.).

Operation of machine10may be initiated by an operator in a cab28located on chassis12. Cab28may include one or more operator controls30, such as, e.g., one or more joysticks, touch screens, buttons, or switches. One or more operator controls30may send one or more signals to controller26. For example, one or more of operator controls30may send an activation signal to activate one or more operating mode of controller26. In one or more examples, one or more of operator controls30may signal controller26to activate one of the systems of controller26, as described below. In another example, one or more of operator controls30may transmit a deactivation signal to controller26to deactivate a system of controller26. Furthermore, in some examples, one or more aspects of controller26may be autonomous, semi-autonomous, and/or remotely controlled, for example, by an operator positioned remote from machine10.

In some examples, operator controls30may be used for commanding movement and positioning of the blade18. For example, operator controls30may be or otherwise include a joystick. In these aspects, moving the joystick forward may lower blade18(i.e., toward ground surface2), and moving the joystick backward may raise blade18(i.e., away from ground surface2). Movement of the joystick by the operator may transmit an operator command signal52to controller26, as shown inFIG.2. Operator command signal52may be indicative of a direction and speed at which the operator commands movement of blade18. One or more aspects of operator controls30, for example, including joystick, may be configured to return automatically to a “neutral” position if the operator is not actively moving operator control30(e.g., a joystick).

With reference toFIGS.1-3, machine10may include one or more sensors to measure position and movement of machine10and/or blade18. For example, machine10may include a speed sensor32to measure a “machine speed”, that is, the speed of machine10moving along ground surface2. Speed sensor32may measure machine speed using any number of known techniques or measurements, including, but not limited to, engine speeds, transmission settings, or direct measurement, e.g., via a global positioning system (“GPS”). Speed sensor32may send a speed signal58, indicative of the machine speed, to controller26.

Furthermore, machine10may be equipped with one or more inertial measurement units (IMUs). For example, machine10may include an IMU located on blade18(i.e., an implement IMU34) and an IMU located on chassis12(i.e., a chassis IMU36). One or more of the IMUs may include one or more accelerometers and one or more gyroscopes. Implement IMU34and/or chassis IMU36may measure acceleration in one or more dimensions or degrees of freedom. Based on acceleration measured by the IMU(s), the IMU(s) and/or controller26may 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 IMU34may measure an angular position and angular velocity of blade18with respect to gravity. Similarly, chassis IMU36may measure an angular position and angular velocity of chassis12with respect to gravity. In these aspects, implement IMU34may help to determine an implement angle and/or an implement pitch, and chassis IMU36may help to determine a chassis angle and/or a chassis pitch. In some examples, each IMU and/or controller26may 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 IMU34may send an implement pitch signal54and/or an implement roll angle signal62, indicative of an implement pitch and/or an implement roll angle, to controller26. Chassis IMU36may send a chassis pitch signal56and/or a chassis roll angle signal64, indicative of a chassis pitch and/or a chassis roll angle, to controller26.

Furthermore, machine10may include one or more additional sensors, for example, coupled to one or more portions of machine10and communicably coupled to controller26. For example, as shown inFIGS.1and2, machine10may include one or more ground surface sensors38, for example, coupled to a forward, a side, or a rear portion of machine10. Ground surface sensor38may include one or more optical sensors, sonar sensors, radar sensors, etc., for example, directed toward ground surface2. Ground surface sensor38may help to detect one or more properties or parameters of ground surface2. For example, ground surface sensor38may detect one or more material properties of ground surface2, for example, to help controller26differentiate between different types of ground surface materials. For example, ground surface sensor38may detect one or more properties of ground surface2to help differentiate between dirt, clay, rock, gravel, etc. In one aspect, ground surface sensor38may help to detect a hardness, density, or other properties of ground surface2, for example, the type of soil or other ground material that machine10is moving over and/or engaging with and/or moving via blade18. Ground surface sensor38may send one or more ground surface signals60, indicative of one or more properties of ground surface2, to controller26.

Machine10may include a track speed sensor40, for example, on or adjacent to one or more of tracks16, for example, on or adjacent to a drive wheel24, one or more idlers, or one or more other portions or components of one or more tracks16. Although not shown, if machine10includes one or more wheels, machine10may include a wheel speed sensor. Track speed sensor40may be used to determine (e.g., either directly or indirectly) the speed of one or more of tracks16. Track speed sensor40may send one or more track speed signals61, indicative of a speed of one or more tracks16, to controller26.

Machine10may include a pitch noise sensor42, for example, on or adjacent to blade18. Pitch noise sensor42may be used to determine one or more noise levels, for example, based on the movement of blade18. Pitch noise sensor42may be coupled to one or more IMUs, for example, on blade18and/or machine10. Pitch noise sensor42may send one or more pitch noise signals63, indicative of a pitch noise of blade18, to controller26. Pitch noise sensor42may 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 sensor42may 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 machine10is cutting (e.g., up or down) relative to gravity. Additionally, in some aspects, pitch noise may increase when machine10is traveling faster across ground surface2, and pitch noise may decrease when machine10is traveling slower across ground surface2.

In one or more aspects, operator control(s)30may also include a user interface, for example, to receive one or more user inputs indicative of one or more material properties of ground surface2and/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 inFIG.2, controller26be a part of a control system100. In control system100, controller26may be coupled to one or more of the aforementioned sensors and an actuator, for example, one or more hydraulic actuators22. As mentioned, hydraulic actuator(s)22may each include hydraulic rod22A that is movable relative to hydraulic cylinder22B. In these aspects, controller26may signal hydraulic actuator(s)22to help control a position and/or movement of blade18. Although not shown, machine10and/or control system100may also include one or more additional sensors, receivers, etc., which may be operably coupled to or otherwise in communication with controller26and/or with one or more other sensors, receivers, etc.

Before proceeding further, it may be beneficial to define certain measurements and terms characterizing the operation of machine10and/or blade18, as illustrated inFIGS.1and2. As referred to herein, a “chassis pitch angle” means the angle of chassis12with respect to a longitudinal axis that is orthogonal with respect to gravity. A “chassis pitch angle rate” refers to the angular velocity of chassis12with respect to the longitudinal axis orthogonal to gravity, that is, the rate of change of chassis pitch angle. Furthermore, a “chassis roll angle” means the angle of chassis12with respect to a transverse axis that is orthogonal with respect to gravity. A “chassis roll angle rate” refers to the angular velocity of chassis12with respect to the transverse axis orthogonal to gravity, that is, the rate of change of chassis roll angle. An “implement roll angle” refers to the angle of rotation of blade18about pivot point X with respect to chassis12. An “implement mainfall angle” ΘMrefers to the angle of blade18with respect to a longitudinal axis orthogonal to gravity. One or more of the foregoing measurements may be taken by one or more of the sensors. For example, implement IMU34may generate an implement pitch signal54indicative, for example, either directly or indirectly, of implement angle. Similarly, chassis IMU36may generate a chassis pitch signal56indicative, for example, either directly or indirectly, of chassis pitch angle and/or chassis pitch angle rate.

Controller26may be in communication with one or more features or portions of machine10, for example, forming control system100. As shown inFIG.2, controller26may receive one or more inputs or signals, including, but not limited to operator command signal52, implement pitch signal54, chassis pitch signal56, speed signal58, ground surface signal60, track speed signal61, implement roll angle signal63, pitch noise signal63, and/or chassis roll angle signal. Based at least in part on these signals, controller26may send one or more outputs or signals, for example, to adjust the movement and position of blade18to compensate for changes in pitch of machine. Additionally, based in part on these signals, controller26may adjust a stabilization level, for example, a stabilization factor104output by stabilization factor system102. Stabilization factor104may be a filter factor, for example, 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 actuator22to control the movement and/or position of blade18). For example, as shown inFIGS.2and3, stabilization factor104may be output and sent to an implement mainfall angle cutoff frequency module118, which may output implement mainfall angle cutoff frequency68, for example, at least partially based on stabilization factor104. As discussed below, implement mainfall angle cutoff frequency module118and the resulting implement mainfall angle cutoff frequency68may help to control a command signal50, for example, output by controller26to control a position and/or movement of blade18. Furthermore, stabilization factor104may either increase or decrease implement mainfall angle cutoff frequency68, or stabilization factor104may not affect implement mainfall cutoff frequency68.

Although not shown, controller26may be coupled to or include one or more memory units, which may contain instructions for controller26to help control a position or movement of blade18. Controller26may be a separate controller on machine10, or may be integrated into a central vehicle controller (e.g., a main power controller, an operation controller, etc.). Alternatively, controller26may be integrated into one or more of control or management systems or modules (e.g., for operating engine14) of machine10, or another dedicated control module on machine10. In one aspect, machine10may be an electrohydraulic dozer, and controller26may control one or more electrical switches or valves in order to control one or more hydraulic cylinders or electrical elements in order to operate machine10.

Controller26may include one or more microprocessors. For example, controller26may embody a single microprocessor or multiple microprocessors. The one or more microprocessors of controller26may be configured to perform any of the operations mentioned herein. For example, controller26may 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 controller26may be non-transitory computer-readable media that store data and/or software routines that may assist controller26in performing its functions, such as the functions of process or method400ofFIG.4, as discussed below. Further, the memory or secondary storage device associated with controller26may also store data received from the various inputs or sensors associated with machine10. Numerous commercially available microprocessors can be configured to perform the functions of controller26. It should be appreciated that controller26could readily embody a general machine controller capable of controlling numerous other machine functions. Various other known circuits may be associated with controller26, including signal-conditioning circuitry, communication circuitry, hydraulic or other actuation circuitry, and other appropriate circuitry.

With continued reference toFIG.2, controller26may include one or more functional modules and systems. For example, controller26may include stabilization factor system102, for example, to determine a stabilization factor104. Additionally, as shown inFIG.3, controller26may include a blade control system150, for example, to process and control the movement and position of blade18during operation of machine10when the operator is not actively instructing movement of blade18. Stabilization factor system102and/or blade control system150may help to maintain blade18at a relatively constant implement mainfall angle ΘMwhile accommodating for low frequency fluctuations the implement mainfall angle ΘMresulting from machine10moving across ground surface2. Controller26may utilize stabilization factor104output by stabilization factor system102in order to adjust a filter factor used to control the position of blade18, for example, used by implement mainfall angle cutoff frequency and thus helping to control the position of blade18based 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 ΘMmay be caused by changes in the trends of the terrain along ground surface2, such as, for example, changes in the slope of ground surface2. High frequency disturbances of the implement mainfall ΘMmay be caused by short bumps or other irregularities along ground surface2. As shown inFIGS.2and3, stabilization factor104may be provided to implement mainfall angle cutoff frequency module118, which may output implement mainfall angle cutoff frequency68at least in part based on stabilization factor104, which may control the movement and/or position of blade18. For example, stabilization factor104may either increase or decrease implement mainfall angle cutoff frequency68, or stabilization factor104may not affect implement mainfall cutoff frequency68.

Stabilization factor system102may include a variable or adaptive stabilization factor104, for example, to be provided to blade18(e.g., via hydraulic actuator22). For example, the level of stabilization of blade18signaled by stabilization factor system102may depend on one or more of operator inputs on operator control30(e.g., a joystick), operator setting selections, machine motion, ground surface properties, and/or one or more other inputs or signals. For example, controller26(i.e., stabilization factor system102) 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 system102) may modify the level of stabilization (e.g., a “filter factor”) based on the deduced or calculated operator intent.

In one example, stabilization factor104may adjust the threshold(s), range(s), etc. used to determine whether a fluctuation of implement mainfall angle ΘMis a low frequency fluctuation or a high frequency fluctuation. For example, as discussed in detail below, stabilization factor system102may include an integrator module106. Integrator module106may help to control the amount or degree to which the position or movement of blade18is stabilized as machine10moves across ground surface2. In one aspect, stabilization factor system102of controller26may include a roading detection module108. In this aspect, integrator module106may be in communication (e.g., send signals) to roading detection module108, which may also adjust stabilization factor104.

As shown inFIG.2, integrator module106may include one or more separate modules. For example, an operator controls module106A may receive and/or analyze operator command signal52, for example, from operator controls30. An implement IMU module106B may receive and/or analyze implement pitch signal54and/or implement roll angle signal62, for example, from implement IMU34. Alternatively, although not shown, integrator module106may include an implement pitch module and a separate implement roll module. Furthermore, a chassis IMU module106C may receive and/or analyze chassis pitch signal56and/or chassis roll angle signal64, for example, from chassis IMU36. Alternatively, although not shown, integrator module106may include a chassis pitch module and a separate chassis roll module. A speed sensor module106D may receive and/or analyze speed signal58, for example, from speed sensor32. A ground surface sensor module106E may receive and/or analyze ground surface signal60, for example, from ground surface sensor38.

Integrator module106may receive signals from one or more of sensors. For example, integrator module106may receive operator command signal52, for example, via operator control(s)30, indicative of an operator's intended blade movement. In one example, operator controls module106A may receive operator command signal52. If operator command signal52is above a first threshold value, then operator controls module106A of integrator module106may increase a stabilization value. If operator command signal52is below a second threshold value, then operator controls module106A of integrator module106may decrease the stabilization value. Furthermore, if operator command signal52is in a certain range, for example, between the first threshold value and the second threshold value, then operator controls module106A of integrator module106may not adjust the stabilization value. In these aspects, if operator command signal52is more than approximately 10% of a maximum operator command signal, then operator controls module106A of integrator module106may increase the stabilization value, for example, by 1. Similarly, if operator command signal52is approximately 0% of the maximum operator command signal, then operator controls module106A of integrator module106may decrease the stabilization value, for example, by 1. If operator command signal52is between approximately 10% and approximately 0% of the maximum operator command signal, then operator controls module106A of integrator module106may not increase or decrease the stabilization value.

Furthermore, integrator module106may receive implement pitch signal54, for example, via implement IMU34. For example, implement IMU module106B may receive implement pitch signal54. If implement pitch signal54is above a first threshold value, then implement IMU module106B of integrator module106may increase a stabilization value. If implement pitch signal54is below a second threshold value, then implement IMU module106B of integrator module106may decrease the stabilization value. Furthermore, if implement pitch signal54is in a certain range, for example, between the first threshold value and the second threshold value, then implement IMU module106B of integrator module106may not adjust the stabilization value. In these aspects, implement IMU module106B of integrator module106may compare a received implement pitch signal54to a previously received implement pitch signal54, for example, to determine a rate of change between sequential implement pitch signals54. If the rate of change between sequential implement pitch signals54is greater than 0.5, then implement IMU module106B of integrator module106may increase the stabilization value, for example, by 1. Similarly, if the rate of change between sequential implement pitch signals54is less than −0.5, then implement IMU module106B of integrator module106may decrease the stabilization value, for example, by 1. If the rate of change between sequential implement pitch signals54is between 0.5 and −0.5, then implement IMU module106B of integrator module106may not increase or decrease the stabilization value.

Alternatively or additionally, integrator module106may receive implement roll angle signal62, for example, via implement IMU34. For example, implement IMU module106B may receive implement roll angle signal62. If implement roll angle signal62is above a first threshold value, then implement IMU module106B of integrator module106may increase a stabilization value. If implement roll angle signal62is below a second threshold value, then implement IMU module106B of integrator module106may decrease the stabilization value. Furthermore, if implement roll angle signal62is in a certain range, for example, between the first threshold value and the second threshold value, then implement IMU module106B of integrator module106may not adjust the stabilization value. In these aspects, implement IMU module106B of integrator module106may compare a received implement roll angle signal62to a previously received implement roll angle signal62, for example, to determine a rate of change between sequential implement roll angle signal62. If the rate of change between sequential implement roll angle signal62is greater than 0.5, then implement IMU module106B of integrator module106may increase the stabilization value, for example, by 1. Similarly, if the rate of change between sequential implement roll angle signal62is less than −0.5, then implement IMU module106B of integrator module106may decrease the stabilization value, for example, by 1. If the rate of change between sequential implement roll angle signal62is between 0.5 and −0.5, then implement IMU module106B of integrator module106may not increase or decrease the stabilization value.

Integrator module106may receive chassis pitch angle signal56, for example, via chassis IMU36. In some aspects, chassis pitch angle signal56may be a pitch angle difference, for example, between a pitch of chassis12and a pitch of blade18. For example, chassis IMU module106C may receive chassis pitch angle signal56. If chassis pitch angle signal56is above a first threshold value, then chassis IMU module106of integrator module106may increase a stabilization value. If chassis pitch angle signal56is below a second threshold value, then chassis IMU module106of integrator module106may decrease the stabilization value. Furthermore, if chassis pitch angle signal56is in a certain range, for example, between the first threshold value and the second threshold value, then chassis IMU module106of integrator module106may not adjust the stabilization value. In these aspects, if chassis pitch angle signal56is 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 module106of integrator module106may increase the stabilization value, for example, by 1. Similarly, if chassis pitch angle signal56is approximately 0 degrees, then chassis IMU module106of integrator module106may decrease the stabilization value, for example, by 1. If chassis pitch angle signal56is 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 module106may not increase or decrease the stabilization value.

Integrator module106may receive chassis roll angle signal64, for example, via chassis IMU36. In some aspects, chassis roll angle signal64may be a roll angle difference, for example, between a roll of chassis12and a roll of blade18. For example, chassis IMU module106C may receive chassis roll angle signal64. If chassis roll angle signal64is above a first threshold value, then chassis IMU module106C of integrator module106may increase a stabilization value. If chassis roll angle signal64is below a second threshold value, then chassis IMU module106C of integrator module106may decrease the stabilization value. Furthermore, if chassis roll angle signal64is in a certain range, for example, between the first threshold value and the second threshold value, then chassis IMU module106C of integrator module106may not adjust the stabilization value. In these aspects, if chassis roll angle signal64is 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 module106C of integrator module106may increase the stabilization value, for example, by 1. Similarly, if chassis roll angle signal64is approximately 0 degrees, then chassis IMU module106C of integrator module106may decrease the stabilization value, for example, by 1. If chassis roll angle signal64is 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 module106C of integrator module106may not increase or decrease the stabilization value.

Integrator module106may receive speed signal58, for example, via speed sensor32. For example, speed sensor module106D may receive speed signal58. If speed signal58is above a first threshold value, then speed sensor module106D of integrator module106may increase a stabilization value. If speed signal58is below a second threshold value, then speed sensor module106D of integrator module106may decrease the stabilization value. Furthermore, if speed signal58is in a certain range, for example, between the first threshold value and the second threshold value, then speed sensor module106D of integrator module106may not adjust the stabilization value. In these aspects, if speed signal58is indicative of a machine speed that is more than approximately five miles per hour, then speed sensor module106D of integrator module106may increase the stabilization value, for example, by 1. Similarly, if speed signal58is indicative of a machine speed that is less than 2 miles per hour, then speed sensor module106D of integrator module106may decrease the stabilization value, for example, by 1. If speed signal58is between approximately 5 miles per hour and approximately 2 miles per hour, then speed sensor module106D of integrator module106may not increase or decrease the stabilization value.

Moreover, integrator module106may receive ground surface signal60, for example, via ground surface sensor38. For example, ground surface sensor module106E may receive ground surface signal60. If ground surface signal60is above a first threshold value, for example, indicative of a first density, hardness, material, or other property of ground surface2, then ground surface sensor module106E of integrator module106may increase a stabilization value. If ground surface signal60is below a second threshold value, for example, indicative of a first density, hardness, material, or other property of ground surface2, then ground surface sensor module106E of integrator module106may decrease the stabilization value. Furthermore, if ground surface signal60is in a certain range, for example, between the first threshold value and the second threshold value, then ground surface sensor module106E of integrator module106may not adjust the stabilization value. In these aspects, if ground surface signal60is indicative of a ground surface2that is denser, harder, rockier, etc., then ground surface sensor module106E of integrator module106may increase the stabilization value, for example, by 1. Similarly, if ground surface signal60is indicative of a ground surface that is less dense, softer, less rocky (i.e., sandier), etc., then ground surface sensor module106E of integrator module106may decrease the stabilization value, for example, by 1. If ground surface signal60is indicative of a moderate material property of ground surface2, then ground surface sensor module106E of integrator module106may not increase or decrease the stabilization value.

Additionally, in some aspects, integrator module106may receive one or more additional signals, for example, from one or more other sensors. Furthermore, in some aspects, integrator module106may receive one or more user inputs, for example, from a user interface in cab28, remote from machine10, or otherwise in communication with controller26.

As mentioned, in some aspects, stabilization factor system102may include roading detection module108. For example, integrator module106may receive signals from one or more of the aforementioned IMUS and/or sensors, and integrator module106may send an intermediate stabilization factor107to roading detection module108. Roading detection module108may receive one or more signals from track speed sensor40and/or pitch noise sensor42. For example, roading detection module108may receive track speed signal61from track speed sensor40, and/or may receive pitch noise signal63from pitch noise sensor42. Based on track speed signal61and/or pitch noise signal62, roading detection module may determine whether machine10is in a roading state. For example, the roading state may correspond to machine10being driven to a new location on the worksite, being driven to a new worksite, being maneuvered on a road, or otherwise being operated without blade18in operation. In these examples, blade18not being in operation may correspond to blade18being raised away or elevated from ground surface2in order to not engage with ground surface2, or otherwise in a position where machine10is not actively grading, shaping, or otherwise intentionally treating ground surface2. If roading detection module108does not detect that machine10is in a roading mode, then roading detection module108allows intermediate stabilization factor107to pass through. In this aspect, roading detection module108sends stabilization factor104to an actuator to control blade18, for example, to hydraulic actuator22. If roading detection module108detects that machine10is in a roading state, roading detection module108modifies intermediate stabilization factor107. For example, in one aspect, when roading detection module108detects that machine10is in the roading state, roading detection module108may maintain a previous stabilization factor (i.e., and not transmit intermediate stabilization factor107). Alternatively, in another aspect, when roading detection module108detects that machine10is in the roading state, roading detection module108may reset the stabilization factor. Resetting the stabilization factor may include transmitting a baseline or standard stabilization factor as stabilization factor104to implement mainfall angle cutoff frequency module118. Alternatively, resenting the stabilization factor may include reducing the stabilization factor104to zero, for example, such that blade18is not stabilized.

In these aspects, if track speed signal61is indicative of a roading speed, then roading detection module108may determine that machine10is 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 signal63is indicative of a roading condition, then roading detection module108may determine that machine10is 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 module108may 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 module108may determine that machine10is in the roading mode and/or adjust stabilization factor106based on one or more of inputs on operator controls30(i.e., the joystick), a position of blade18, for example, relative to machine chassis12, the speed of tracks16, the load of engine14, pitch of machine chassis12, etc. In these aspects, roading detection module108may detect roading when either track speed signal61or pitch noise signal63is above one or more thresholds. In another aspect, roading detection module108may only detect roading if both track speed signal61and pitch noise signal63are above respective thresholds.

In another aspect, instead of intermediate stabilization factor107being sent from integrator module106to roading detection module108, roading detection module108may be integral with integrator module106, and may override or otherwise adjust any signals to be emitted from integrator module106(e.g., to hydraulic actuator22) when roading is detected. In this aspect, track speed sensor40and/or pitch noise42may send track speed signal61and/or pitch noise signal63to integrator module106. Furthermore, although not shown, roading detection module108may include one or more separate modules, for example, a track speed sensor module to receive track speed signal61from track speed sensor40and/or a pitch noise sensor module to receive pitch noise signal63from pitch noise sensor42.

FIG.3illustrates additional portions or components of controller26. As mentioned above, controller26may receive one or more inputs or signals, including, but not limited to operator command signal52, implement pitch signal54, chassis pitch signal56, and speed signal58. Based in part on these signals, the controller26may adjust the movement and position of blade18to compensate for changes in pitch, roll, etc. of machine10.

Controller26may include one or more additional function modules and systems, such as, e.g., blade control system150to process and control the movement and position of blade18. Blade control system150may maintain blade18at a relatively constant implement mainfall angle ΘMwhile accommodating for low frequency fluctuations of the implement mainfall angle ΘMresulting from machine10moving across ground surface2. Blade control system150may adjust the position of blade18based 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 ΘMmay be caused by changes in the trends of the terrain along ground surface2, such as, e.g., changes in the slope of ground surface2. High frequency disturbances of the implement mainfall angle ΘMmay be caused by short bumps or other irregularities along ground surface2.

Blade control system150may include a module114, for example, a chassis pitch angle module114, to determine the chassis pitch angle164based on the chassis pitch signal56. Blade control system150may include another module112, for example, an implement angle module112, to determine the implement angle162based on the implement pitch signal54. Blade control system150may include a latch120configured to receive the operator command signal52. Latch120may trigger based on the operator command signal52. For example, transitioning operator control30, e.g., a joystick, to the neutral position may send an operator command signal52to controller26that triggers latch120. Once triggered, latch120may pass the current implement angle162through latch120to generate the last commanded implement angle126. The last commanded implement angle126may be indicative of the implement angle162measured at the time operator control30(e.g., a joystick) transitions to the neutral position, for example, indicative of the most recently commanded implement angle. Another module134, for example, a comparison module134, may compare chassis pitch angle164with implement angle162to determine the implement mainfall angle ΘM. Comparison module134may transmit the implement mainfall angle ΘMto another module138, for example, a difference angle module138.

Controller26may include a low pass filter122. Low pass filter122may be weighted or adjusted based on a machine speed166and/or implement mainfall angle cutoff frequency68. Implement mainfall angle cutoff frequency module118may determine the implement mainfall angle cutoff frequency68. The implement mainfall angle cutoff frequency68may be a static value stored in memory accessible by the controller26. In at least some examples, however, implement mainfall angle cutoff frequency68may be adaptively determined based on perceived operator application of machine10, 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 module118may receive stabilization factor104, for example, from one or more of integrator module104and/or roading detection module108. Stabilization factor104may either increase or decrease implement mainfall angle cutoff frequency68, or stabilization factor104may not affect implement mainfall cutoff frequency68. The implement mainfall angle cutoff frequency68may ensure that machine speed166is not used to adjust the low pass filter122if machine10is moving too slowly or too fast for low pass filter122to accurately filter the chassis pitch angle164. Low pass filter122may be adjusted based on a weight factor, K1, determined at a module, for example, a weight factor module124. Weight factor module124may compare machine speed166and implement mainfall angle cutoff frequency68. Low pass filter122may filter the chassis pitch angle164to determine a filtered chassis pitch angle128. By utilizing low pass filter122, filtered chassis pitch angle128may be determined in part based on the change in the chassis pitch angle164over time, along with stabilization factor104received from stabilization factor system102, as discussed above.

Blade control system150may include another module130, for example, a target mainfall angle module130, which may compare the last commanded implement angle126to filtered chassis pitch angle128to determine a target implement mainfall angle132. The implement mainfall angle ΘMmay be compared to the target implement mainfall angle132at difference angle module138to determine a difference angle140. At another module142, for example, a command signal module142, controller26may generate command signal50for directing movement of blade18based on difference angle140. In some examples, command signal module142may correspond to a distinct controller, e.g., a PID controller. Command signal50may initiate movement of blade18to the target implement mainfall angle132, e.g., by actuating one or more of hydraulic actuator(s)22.FIG.4is a flow diagram portraying an exemplary method400that may be performed by control system100to adjust automatically stabilization factor104and/or the position or movement of blade18during an operation (i.e., a grading or earth moving operation). For example, as discussed above, when machine10is operating, control system100may monitor user inputs (i.e., via operator control(s)30) and/or one or more sensed or measured parameters, integrate the user inputs and/or sensed or measured parameters, and/or modify stabilization factor104in the adjustment and/or positioning of blade18. Furthermore, as discussed, control system100may detect whether machine10is in a roading mode (i.e., via roading detection module108), in which case control system100may not stabilize blade18.

Method400includes an initial step402, which includes initiating or beginning a machine operation. For example, step402may include powering up or otherwise starting machine10and operating machine10. Operating machine10may include powering engine14, manipulating blade18, and/or activating one or more of hydraulic actuator22, control system100, a navigation system, an illumination system, or other aspects of machine10. Step402may include an operator action, for example, starting machine10and/or directing machine10to perform an operation (e.g., a grading or earth moving operation).

Next, method400includes a step404, which includes automatically adjusting a stabilization factor and controlling a position (or movement) of an implement. As discussed above, control system100may include operator control(s)30and a plurality of sensors. Controller26, for example, stabilization factor system102, may receive one or more signals from operator control(s)30and/or one or more of the plurality of sensors. Stabilization factor system102includes integrator module106, which analyzes and integrates or otherwise combines the received signals to output or generate intermediate stabilization factor107. In some aspects, intermediate stabilization factor107may pass through roading detection module108, and stabilization factor104may be sent to implement mainfall angle cutoff frequency module118(FIGS.2and3) and/or applied to one or more other aspects of machine10discussed herein. In these aspects, stabilization factor104may be used to adjust command signal50to control the movement and/or position of blade18, for example, by adjusting the implement mainfall angle cutoff frequency68used to modify the operator command signal52(FIG.3). As mentioned above, stabilization factor104may either increase or decrease implement mainfall angle cutoff frequency68, or stabilization factor104may not affect implement mainfall cutoff frequency68. Hydraulic actuator22may then control the position and/or movement of blade18, for example, based on command signal50.

Method400then includes a step406, which includes continuing the operation and continuously adjusting the stabilization factor and controlling the position of the implement. As discussed herein, operator control(s)30and/or one or more of the plurality of sensors may continuously or periodically send one or more signals to stabilization factor system102(i.e., to integrator module106). In this aspect, integrator module106may continuously adjust stabilization factor104, which may then be implemented by hydraulic actuator22and/or one or more other aspects of machine10discussed herein, in order to control the position and/or movement of blade18throughout the course of the operation.

In some aspects, method400includes a step408, which includes a determination of whether roading is detected. As discussed above, stabilization factor system102may include roading detection module108. Roading detection module108may receive intermediate stabilization factor107from integrator module106. Additionally, roading detection module108may receive one or more signals from one or more sensors, for example, track speed sensor40and/or pitch noise sensor42. If roading detection module108does not detect roading, then method400may return to step406. However, if roading detection module108detects roading (e.g., based on a received track speed signal61and/or a received pitch noise signal63), then method400may proceed to step410. In these aspects, when detecting roading, roading detection module108may maintain, reset, or otherwise adjust intermediate stabilization factor107before sending the adjusted stabilization factor104to hydraulic actuator22and/or one or more other aspects of machine10discussed herein. For example, step410may include disabling the automatic adjustment of the stabilization factor and the control of the position of the implement. In some aspects, if roading detection module108no longer detects roading, then method400may also then return to step406.

INDUSTRIAL APPLICABILITY

The present disclosure may be applicable in systems and methods for controlling an implement on a machine, such as, e.g., blade18on machine10. During operation, movement of machine10across uneven terrain of ground surface2may cause chassis12and/or blade18to pitch forward and aft, roll side-to-side, or otherwise move, which may affect the position and/or movement of blade18. The position and/or movement of blade18may affect the grade cut into ground surface2by blade18. Stabilization factor system102and/or other aspects of control system100, as discussed herein, may help to control and/or augment position and/or movement of blade18. For example, stabilization factor system102and/or other aspects of control system100may help to adjust the implement mainfall angle ΘMand/or refine instructed movement of blade18. Accordingly, stabilization factor system102and/or other aspects of control system100may help to produce a smooth grading profile of ground surface2by augmenting and/or adjusting the implement mainfall angle ΘMor operator commands to compensate for unintentional changes in the pitch, angle, speed, etc. of machine10, chassis12, and/or blade18.

Furthermore, stabilization factor system102may provide an adjustably filter factor or stabilization factor104. Stabilization factor104may be provided to implement mainfall angle cutoff frequency module118, 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 actuator22to control the movement and/or position of blade18). For example, stabilization factor104may either increase or decrease implement mainfall angle cutoff frequency68, or stabilization factor104may not affect implement mainfall cutoff frequency68. Alternatively or additionally, stabilization factor104may be provided to weight factor module124, for example, which may adjust the weight factor K1 and/or another adjustment of one or more sensed measurements. In these aspects, control system100may help machine10to 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 system100may help to maintain blade18in a highly stable position relative to ground surface2when machine10is operating on a flat surface. Moreover, control system100may also help to move and/or adjust the position of blade18when machine10is operating on a bumpy, sloped, or otherwise unstable terrain. Furthermore, control system100may allow for the adjustment of the movement and/or position of blade18to be done with minimal user input.

Furthermore, stabilization factor system102, for example, via roading detection module108, may help machine10to detect when stabilization of implement18is not necessary, for example, when blade18is not engaged with and/or is elevated from ground surface2and/or when machine10is in a roading mode. As discussed, roading detection module108may receive one or more signals from, for example, track speed sensor40and/or pitch noise sensor42. In these aspects, when track speed signal61indicates a certain speed and/or when pitch noise signal63indicates that blade18is not engaged with and/or is elevated from ground surface2, roading detection module108may maintain, reset, or otherwise adjust intermediate stabilization factor107before sending the adjusted stabilization factor104to hydraulic actuator22and/or one or more other aspects of machine10discussed herein. For example, roading detection module108may help to temporarily reduce the operation level of control system100and/or reduce the movements and/or positioning applied to blade18when machine10is in a roading mode. Additionally, roading detection module108may allow for the roading detection to occur automatically, that is, without an operator manually activating stabilization (i.e., in steps304and306) or deactivating stabilization (i.e., in step410).

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.