US-12618219-B2 - Automated coupling of an implement to an implement carrier of a power machine

US12618219B2US 12618219 B2US12618219 B2US 12618219B2US-12618219-B2

Abstract

Disclosed embodiments include power machine, control systems for power machines, and methods of controlling a power machine to automatically couple an implement to an implement carrier of the power machine. Sensors are used to identify positions of a power machine and of an implement, such as a bucket, to be coupled to the implement carrier of the power machine. Control methods are implemented to allow the power machine to be automatically controlled to couple the implement to the implement.

Inventors

Christopher Clark
Aman Fatehpuria
Jingnan Shi
Jessica A. Lupanow
David E. Olumese
Gabriel L. Rubin
Darien J. Joso
Kayla Yamada

Assignees

DOOSAN BOBCAT NORTH AMERICA, INC.

Dates

Publication Date: 20260505
Application Date: 20190501

Claims (13)

1 . A power machine comprising: a frame; a power system supported by the frame; a traction system supported by the frame and powered by the power system to controllably propel the power machine over a support surface, the traction system including drive motors configured to cause the traction system to move the power machine over the support surface; an implement interface including an implement carrier configured to receive and secure an implement to the power machine; a lift arm assembly having at least one lift arm which supports the implement interface; at least one lift actuator coupled to the lift arm assembly and to the frame and configured to raise and lower the at least one lift arm; at least one tilt actuator coupled to the implement interface and to the lift arm assembly and configured to rotate the implement carrier relative to the lift arm assembly; a sensor system configured to provide data indicative of a position of the power machine relative to the implement; a control system configured to control the traction system to automatically guide the power machine to the implement and to control the power machine to automatically couple the implement to the implement carrier, wherein the control system is configured to control the drive motors, as a function of the position of the power machine relative to the implement as indicated by the data from the sensor system, to automatically guide the power machine to the implement, and wherein the control system is further configured to automatically control the at least one lift actuator to raise or lower the at least one lift arm for automatic coupling of the implement to the implement carrier, and to automatically control the at least one tilt actuator to rotate the implement carrier while automatically coupling the implement to the implement carrier, wherein the control system is configured to determine a desired position state of the power machine and to compare the desired position state to a current position state estimate of the power machine to determine a difference between the current position state estimate and the desired position state, the controller generating a control input, required to move the power machine, as a function of the difference between the current position state estimate and the desired position state.
2 . The power machine of claim 1 , wherein the control system is configured to determine the desired position state of the power machine using the data from the sensor system.
3 . The power machine of claim 1 , wherein the control system is configured to: generate a current x position of the power machine, a current y position of the power machine, and a current angular position of the power machine relative to an angular position in which the power machine would be positioned for coupling the implement to the implement carrier; generate a next desired x position of the power machine and a next desired y position of the power machine that move the power machine toward the implement; calculate a desired angular position as a function of a difference between the desired y position and the current y position and as a function of a difference between the desired x position and the current x position; calculate a difference between the desired angular position and the current angular position; determine a desired forward velocity as a function of a difference between the current x position and the desired x position and as a function of a difference between the current y position and the desired y position; determine a desired rotational velocity as a function of the difference between the desired angular position and the current angular position; determine whether the difference between the desired angular position and the current angular position is greater than a threshold value; generate the control input, required to move the power machine, as a function of the desired rotational velocity if the difference between the desired angular position and the current angular position is greater than the threshold value; and generate the control input, required to move the power machine, as a function of the desired forward velocity if the difference between the desired angular position and the current angular position is less than the threshold value.
4 . The power machine of claim 1 , wherein the control system is a proportional controller.
5 . The power machine of claim 1 , wherein the control system is a point tracking controller.
6 . The power machine of claim 1 , wherein the control system is a proportional integral derivative (PID) controller.
7 . The power machine of claim 1 , wherein the control system is a sequential proportional integral derivative (SPID) controller.
8 . A method of coupling an implement to an implement carrier of a power machine, wherein the power machine comprises a lift arm assembly having at least one lift arm which supports the implement carrier, at least one lift actuator coupled to the lift arm assembly and to a frame and configured to raise and lower the at least one lift arm, and at least one tilt actuator coupled to the implement carrier and to the lift arm assembly and configured to rotate the implement carrier relative to the lift arm assembly, the method comprising: obtaining data, from a sensor system, indicative of a position of the power machine relative to the implement; controlling a traction system of the power machine, using a control system and as a function of the data indicative of the position of the power machine relative to the implement, to automatically guide the power machine over a support surface to the implement, wherein the traction system of the power machine further comprises drive motors configured to cause the traction system to move the power machine over the support surface, and wherein controlling the traction system further comprises using the control system to generate a control input, as a function of the position of the power machine relative to the implement as indicated by the data from the sensor system, and controlling the drive motors using the control input to automatically guide the power machine to the implement, wherein using the control system to generate the control input further comprises: determining a desired position state of the power machine using the data from the sensor system; comparing the desired position state to a current position state estimate of the power machine to determine a difference between the current position state estimate and the desired position state; and generating the control input as a function of the difference between the current position state estimate and the desired position state; and using the control system to automatically control the at least one lift actuator to raise or lower the at least one lift arm for automatic coupling of the implement to the implement carrier and to automatically control the at least one tilt actuator to rotate the implement carrier while automatically coupling the implement to the implement carrier when the power machine is in position proximate the implement.
9 . The method of claim 8 , and further comprising: generating a current x position of the power machine, a current y position of the power machine, and a current angular position of the power machine relative to an angular position in which the power machine would be positioned for coupling the implement to the implement carrier; generating a next desired x position of the power machine and a next desired y position of the power machine that move the power machine toward the implement; calculating a desired angular position as a function of a difference between the desired y position and the current y position and as a function of a difference between the desired x position and the current x position; calculating a difference between the desired angular position and the current angular position; determining a desired forward velocity as a function of a difference between the current x position and the desired x position and as a function of a difference between the current y position and the desired y position; determining a desired rotational velocity as a function of the difference between the desired angular position and the current angular position; determining whether the difference between the desired angular position and the current angular position is greater than a threshold value; generating the control input, required to move the power machine, as a function of the desired rotational velocity if the difference between the desired angular position and the current angular position is greater than the threshold value; and generating the control input, required to move the power machine, as a function of the desired forward velocity if the difference between the desired angular position and the current angular position is less than the threshold value.
10 . The method of claim 8 , wherein using the control system to generate the control input further comprises using a proportional controller to generate the control input.
11 . The method of claim 8 , wherein using the control system to generate the control input further comprises using a point tracking controller to generate the control input.
12 . The method of claim 8 , wherein using the control system to generate the control input further comprises using a proportional integral derivative (PID) controller to generate the control input.
13 . The method of claim 8 , wherein using the control system to generate the control input further comprises using a sequential proportional integral derivative (SPID) controller to generate the control input.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 62/665,160, filed May 1, 2018, and U.S. provisional patent application Ser. No. 62/665,167, filed May 1, 2018, the contents of which are hereby incorporated by reference in their entireties. BACKGROUND This disclosure is directed toward power machines. More particularly, this disclosure is directed toward systems for, and methods of, automatically coupling an implement to an implement carrier of a power machine. Power machines, for the purposes of this disclosure, include any type of machine that generates power for the purpose of accomplishing a particular task or a variety of tasks. One type of power machine is a work vehicle. Work vehicles are generally self-propelled vehicles that have a work device, such as a lift arm (although some work vehicles can have other work devices) that can be manipulated to perform a work function. Work vehicles include loaders, excavators, utility vehicles, tractors, and trenchers, to name a few examples. Many power machines have implement carriers to which various types of implements can be removably coupled. For example, various loaders have an implement carrier rotatably coupled to a lift arm for receiving various implements. Such implement carriers advantageously allow an operator to use various implements on a single machine and to change implements as may be desired. Typically, coupling an implement, such as a bucket, to an implement carrier of a power machine requires a series of operational steps by the operator of the power machine, including putting the power machine in alignment with the implement. The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. SUMMARY Disclosed embodiments include a power machine, control systems for power machines, and methods of controlling a power machine to automatically couple an implement to an implement carrier of the power machine. Sensors are used to identify positions of a power machine and of an implement, such as a bucket, to be coupled to the implement carrier of the power machine. Control methods are implemented to allow the power machine to be automatically controlled to couple the implement to the implement. Disclosed embodiments include power machines (100; 200; 300) having a frame (110; 210), a power system (120; 220) supported by the frame, a traction system (140: 240) supported by the frame and powered by the power system to controllably propel the power machine over a support surface, and an implement interface (170; 270) including an implement carrier (272; 370) configured to receive and secure an implement (305) to the power machine. The power machines also have a control system (400; 450; 500) configured to control the traction system to automatically guide the power machine to the implement and to control the power machine to automatically couple the implement to the implement carrier. In some embodiments, the power machines further comprise a sensor system (452) configured to provide data indicative of a position of the power machine relative to the implement. Drive motors (454) of the traction system are configured to cause the traction system to move the power machine over the support surface. In these embodiments, the control system is configured to control the drive motors, as a function of the position of the power machine relative to the implement as indicated by the data from the sensor system, to automatically guide the power machine to the implement. In some embodiments, the power machines further comprise a lift arm assembly (230) having at least one lift arm (234) which supports the implement interface. At least one lift actuator (238; 456) is coupled to the lift arm assembly and to the frame and is configured to raise and lower the at least one lift arm. At least one tilt actuator (235; 458) is coupled to the implement interface and to the lift arm assembly and is configured to rotate the implement carrier relative to the lift arm assembly. The control system is further configured to control the at least one lift actuator and the at least one tilt actuator to automatically couple the implement to the implement carrier. In some embodiments, the control system is configured to determine a desired position state of the power machine and to compare the desired position state to a current position state estimate of the power machine to determine a difference between the current position state estimate and the desired position state. The controller is also configured to generate a control input, required to move the power machine, as a function of the difference between the current position state estimate and the desired position state. In some embodiments, the control system is configured to determine the desired position state of the power machi