Ground-working machine dynamic counterbalance

Abstract

Embodiments herein relate to ground-working machines having dynamic counterbalance. In an embodiment, a ground-working machine is included having a vehicle having a plurality of vehicle ground-engaging rotatable members, an electric motor to drive one or more vehicle ground-engaging rotatable members, a working assembly, and a connection assembly. The connection assembly is configured to apply a counterbalance pressure to the working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members. The ground working machine includes a control system in communication with the electric motor and configured to receive a torque value output. The control system is configured to based on the torque value, determine whether to apply a counterbalance pressure the working assembly, determine a counterbalance value, and apply a counterbalance pressure of the determined counterbalance to the working assembly.

Description

[0001] GROUND-WORKING MACHINE DYNAMIC COUNTERBALANCE

[0002] This application is being filed as a PCT International Patent application on October 25, 2024 in the name of The Toro Company, a U.S. national corporation, applicant for the designation of all countries and John R. Van Beek and Matthew J. Decker all Citizens of the U.S., inventors for the designation of all countries and claims priority to U.S. Provisional Patent Application No. 63 / 545,698, filed October 25, 2023, the content of which is herein incorporated by reference in its entirety.

[0003] Field

[0004] Embodiments herein relate to ground-working machines, and more specifically to ground-working machines having dynamic counterbalance.

[0005] Background

[0006] Ground-working machines can have many possible numbers and configurations of working assemblies. There are times when it would be desirable to transfer at least a portion of the weight of the working assemblies back to the vehicle to put more downforce on the vehicle, thereby increasing its traction.

[0007] Summary

[0008] In a first aspect, a ground-working machine can be included having a vehicle including a plurality of vehicle ground-engaging rotatable members configured to contact a ground surface, a first electric motor to drive one or more of the plurality of vehicle ground-engaging rotatable members, and a first working assembly including a ground-working unit and a plurality of working assembly ground-engaging rotatable members configured to contact the ground surface. The ground-working machine can include a first connection assembly, wherein the first connection assembly attaches the first working assembly to the vehicle. The first connection assembly is configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members. The groundworking machine can include a control system in communication with the first electric motor and configured to receive a first torque value output indicating first applied torque, wherein first applied torque can be the torque applied by the first electric motor to drive the one or more of the pluralities of vehicle ground-engaging rotatable members. The control system can be configured to be based on the first torque value, determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly, if a determination can be made to apply or change a counterbalance pressure at the first working assembly, determine a counterbalance value based on the first torque value, and apply a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.

[0009] In a second aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the first electric motor can be configured to drive a first axle operably connected to a first rotatable member and a second rotatable member of the plurality of vehicle ground-engaging rotatable members.

[0010] In a third aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, further can include a second electric motor configured to drive a second axle operably connected to a third rotatable member and a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members, wherein the control system can be in communication with the second electric motor and can be configured to receive a second torque value output indicating second applied torque, wherein second applied torque can be the torque applied by the second electric motor to the third rotatable member and the fourth rotatable member.

[0011] In a fourth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to increase the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque can be below a lower torque threshold.

[0012] In a fifth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to decrease the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque can be above an upper torque threshold.

[0013] In a sixth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to: increase the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque can be below a lower torque threshold and decrease the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque can be above an upper torque threshold.

[0014] In a seventh aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, wherein: the first electric motor can be configured to drive a first rotatable member of the plurality of vehicle groundengaging rotatable members, a second electric motor can be configured to a second rotatable member of the plurality of vehicle ground-engaging rotatable members, a third electric motor can be configured a third rotatable member of the plurality of vehicle ground-engaging rotatable members, and a fourth electric motor can be configured to a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members, wherein the control system can be configured to: receive the first torque value output indicating the first applied torque, wherein the first applied torque can be torque applied by the first electric motor to the first rotatable member, receive a second torque value output indicating the second applied torque, wherein the second applied torque can be torque applied by the second electric motor to the second rotatable member, receive a third torque value output indicating the third applied torque, wherein the third applied torque can be torque applied by the third electric motor to the third rotatable member, and receive a fourth torque value output indicating the fourth applied torque, wherein the fourth applied torque can be torque applied by the fourth electric motor to the fourth rotatable member.

[0015] In an eighth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the working assembly ground-engaging rotatable members remain in contact with a ground surface while the determined counterbalance pressure of the determined counterbalance value can be applied to the first working assembly.

[0016] In a ninth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, wherein each connection assembly can be configured to raise the one working assembly from a working position in which the working assembly ground-engaging rotatable members remain in contact with a ground surface to a raised position in which the working assembly ground-engaging rotatable members can be raised above the ground surface.

[0017] In a tenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the working assembly ground-engaging rotatable members can be configured to follow the ground surface independently of the vehicle ground-engaging rotatable members.

[0018] In an eleventh aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to: compare the first torque value to a maximum expected torque value, and increase the counterbalance pressure to the first working assembly if the first torque value can be above the maximum torque expected value.

[0019] In a twelfth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, further can include a slope sensor configured to output a slope value indicating a slope of the ground-working machine with respect to a horizontal reference plane, wherein the control system can be configured to adjust the maximum expected torque value based on the slope value.

[0020] In a thirteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to increase the maximum expected torque value as the slope value increases.

[0021] In a fourteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, wherein when the first torque value can be above the maximum expected torque value, if the control system receives a second torque value indicating a rapid decrease in the torque applied by the first electric motor, the control system can be configured to increase the counterbalance pressure to the first working assembly.

[0022] In a fifteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the control system can be configured to: receive a signal from the vehicle that regenerative braking can be activated, not increase the counterbalance pressure to the first working assembly upon detecting that regenerative braking can be activated.

[0023] In the sixteenth aspect, a method of operating a ground-working machine is included. The machine can include a vehicle can include a first electric motor and a plurality of vehicle ground-engaging rotatable members and a first working assembly can include a plurality of working assembly ground-engaging rotatable members, wherein the first working assembly can be operatively connected to the vehicle by a first connection assembly, wherein the first connection assembly can be configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members. The method can include receiving a first torque value output indicating first applied torque, wherein first applied torque can be torque applied by the first electric motor to drive the one or more of the plurality of vehicle ground -engaging rotatable members. The method can include based on the first torque value, determining whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly. The method can include if a determination can be made to apply or change a counterbalance pressure at the first working assembly, determining a counterbalance value based on the first torque value. The method can include applying a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.

[0024] In a seventeenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, further can include: comparing the first torque value to a maximum expected torque value and increasing the counterbalance pressure to the first working assembly if the first torque value can be above the maximum torque expected value.

[0025] In an eighteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the vehicle further can include a slope sensor configured to output a slope value indicating a slope of the groundworking machine with respect to a horizontal reference plane, the method further can include adjusting the maximum expected torque value based on the slope value.

[0026] In a nineteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the method can further include increasing the maximum expected torque value as the slope value increases.

[0027] In a twentieth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, further can include: detecting that the first torque value can be above the maximum expected torque value, receiving a second torque value indicating a rapid decrease in the torque applied by the first electric motor, and increasing the counterbalance pressure to the first working assembly. This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which is not to be taken in a limiting sense. The scope herein is defined by the appended claims and their legal equivalents.

[0028] Brief Description of the Figures

[0029] Aspects may be more completely understood in connection with the following figures (FIGS.), in which:

[0030] FIG. l is a perspective view of a ground-working machine in accordance with various embodiments herein.

[0031] FIG. 2 is a front view of the ground-working machine of FIG. 1 in accordance with various embodiments herein.

[0032] FIG. 3 is a top view of the ground-working machine of FIG. 1 in accordance with various embodiments herein.

[0033] FIG. 4 is a perspective view of a working assembly in accordance with various embodiments herein.

[0034] FIG. 5 is a schematic view of a portion of a ground-working machine in accordance with various embodiments herein.

[0035] FIG. 6 is a schematic view of a portion of a ground-working machine in accordance with various embodiments herein.

[0036] FIG. 7 is a front view of a connection assembly in accordance with various embodiments herein.

[0037] FIG. 8 is a side view of a connection assembly in accordance with various embodiments herein.

[0038] FIG. 9 is a schematic diagram of a hydraulic system for a ground-working machine in accordance with various embodiments herein.

[0039] FIG. 10 is a schematic diagram of a counterbalance system in accordance with various embodiments herein.

[0040] FIG. 11 is a schematic diagram of a ground-working machine on a ground surface in accordance with various embodiments herein. FIG. 12 is a graph showing electric traction motor current vs. ground speed in accordance with various embodiments herein.

[0041] FIG. 13 is a plot showing electric traction motor torque and incline of a ground-working machine over time in accordance with various embodiments herein.

[0042] FIG. 14 is a plot showing electric traction motor torque and incline of a ground-working machine over time in accordance with various embodiments herein.

[0043] FIG. 15 is a method for operating a round-working machine in accordance with various embodiments herein.

[0044] While embodiments are susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings and will be described in detail. It should be understood, however, that the scope herein is not limited to the particular aspects described. On the contrary, the intention is to cover modifications, equivalents, and alternatives falling within the spirit and scope herein.

[0045] Detailed Description

[0046] A ground-working machine can include a vehicle having at least one electric motor configured to drive a plurality of vehicle ground-engaging rotatable members and at least one working assembly. As mentioned above, there are times when it would be desirable to transfer at least a portion of the weight of the working assemblies back to the vehicle to put more downforce on the vehicle, thereby increasing its traction. Accordingly various embodiments herein describe a groundworking machine configured to dynamically adjust the counterbalance pressure applied to each of its working assemblies. The counterbalance pressure applied to a working assembly can shift weight from the working assembly to the vehicle. The counterbalance pressure can be dynamically adjusted based on a number of factors, including at least the torque applied by one or more electric motors to the vehicle ground-engaging rotatable members.

[0047] In various embodiments, the ground-working machine can include a vehicle having a plurality of vehicle ground-engaging rotatable members configured to contact the ground and at least one electric motor to drive one or more of the vehicle ground-engaging rotatable members. The ground-working machine can further include a control system in communication with at least one electric motor. In various embodiments, the control system is configured to receive a torque value output that is indicative of a torque applied by the electric motor to drive the one or more associated vehicle ground-engaging rotatable members.

[0048] Based on the received torque value, the control system is configured to determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to each of the one or more working assemblies via its connection assembly. If a determination is made to apply or change a counterbalance pressure at a particular working assembly, the control system is configured to determine a counterbalance value based on the torque value. The control system is configured to apply a counterbalance pressure of the determined counterbalance value via a connection assembly to each particular working assembly for which a determination was made to apply or change a counterbalance pressure. In various embodiments, the working assembly ground-engaging rotatable members of each working assembly remain in contact with the ground surface while the determined counterbalance pressure is applied to the working assemblies.

[0049] Ground-Working Machine

[0050] Referring now to FIG. 1, a perspective view of a ground- working machine is shown in accordance with various embodiments herein. In the example of FIG. 1, ground-working machine 100 is a mower configured to cut grass on a turf surface. In other examples, the ground-working machine 100 can be configured for mowing other plants, spraying, debris collection, raking, aerating, or the like.

[0051] The ground-working machine 100 includes a vehicle 110 operably connected by one or more connection assemblies 122 to a plurality of working assemblies 120, also referred to as ground-working assemblies. In various embodiments, the connection assemblies 122 are in communication with a hydraulic system 124 disposed in the vehicle 110.

[0052] In the example of FIG. 1, the vehicle 110 is a traction vehicle having vehicle ground-engaging rotatable members 112. The vehicle 110 can have an operator seat 114 and operator controls, such as a steering wheel 115 and a user interface 130. The vehicle 110 further includes many additional internal and external elements, such as an engine, transmission, etc (not shown). The operator seat 114 faces toward a front 140 of the vehicle 110. The front 140 is in the direction of most typical forward motion from the operator seat 114. The vehicle 110 rides on two or more vehicle ground-engaging rotatable members 112. In the example of FIG. 1, the vehicle 110 has four vehicle groundengaging rotatable members 112, but in alternative examples the vehicle can have two, three, five or more vehicle ground-engaging rotatable members. The vehicle ground-engaging rotatable members 112 contact the ground independently of the working assemblies 120.

[0053] The ground-working machine 100 is provided with one or more working assemblies 120. In the example of FIG. 1, the ground-working machine 100 is provided with three working assemblies 120. In alternative examples, the groundworking machine 100 could be provided with fewer working assemblies or more working assemblies 120, such as a single working assembly, two working assemblies, four working assemblies, five working assemblies or eight or more working assemblies. In the example of FIG. 1, the ground-working machine includes a singular large working assembly at the front 140 of the vehicle 110 and two smaller working assemblies at each side of the vehicle. In some embodiments, the working assemblies 120 can be substantially similar to each other in size and / or type. Alternatively multiple sizes and / or types of working assembly 120 can be associated with a single vehicle 110.

[0054] In various embodiments, the working assemblies 120 can be distributed in a gang configuration. In the example of FIG. 1, vehicle 110 carries three working assemblies 120 in a 1-2 gang configuration comprising a front row of one working assembly followed by a rear row of two working assemblies. In various embodiments, the working assemblies 120 in the rear row are placed to cover the gaps between the working assemblies in the front row.

[0055] In the example of FIG. 1, the working assemblies 120 are rotary ground cutting working assemblies, each having a blade or blades (not shown) that rotates around a substantially vertical axis. In alternative embodiments, the working assemblies 120 can incorporate a reel cutting unit, a disc cutting unit, a flail cutting unit, or another type of cutting unit. In further embodiments, the working assemblies 120 can be configured for spraying, debris collection, raking, or aerating, or the like.

[0056] In various embodiments, each working assembly 120 can have two or more working assembly ground-engaging rotatable members 121. The working assembly ground-engaging rotatable members 121 can follow the ground surface independently from the vehicle ground-engaging rotatable members 112. In various embodiments, each working assembly is configured to be driven by the vehicle and includes working assembly ground-engaging rotatable members that follow the ground independently of the vehicle ground-engaging rotatable members 112.

[0057] Ground-Working Machine in Working Position

[0058] In the example of FIG. 1, the plurality of working assemblies 120 are placed in a working position. A working position is defined herein as the position in which the working assembly ground-engaging rotatable members 121 are in contact with a ground surface. When in the working position, the working assemblies 120 are configured to be substantially parallel to the ground surface. When in the working position, the working assemblies 120 are individually self-supporting for movement over the ground through the working assembly ground-engaging rotatable members 121 carried on the front and rear of each working assembly 120. In various embodiments, the working assemblies 120 are provided with a floating motion in two degrees of freedom in the working position. In the working position, each working assembly 120 can pitch about a transverse pitch axis and can roll about a fore-and-aft roll axis.

[0059] Ground-Working Machine in Raised Position (FIG. 2)

[0060] Referring now to FIG. 2, a front perspective view of ground-working machine is shown in accordance with various embodiments herein. In the example of FIG. 2, the left and right working assemblies 120 are placed in a raised position. A raised position is defined herein as the position in which the working assembly groundengaging rotatable members 121 are raised above the ground surface. In various embodiments, each connection assembly 122 is configured to move its respective working assembly 120 between the working position and the raised position. In the example of FIG. 2, the front working assembly remains in the lower position, but it is possible to also raise the front working assembly.

[0061] In some embodiments, the user interface 130 can include a lift function configured to receive input from a user requesting movement of one or more of the working assemblies to a raised position. In some embodiments, all of the working assemblies 120 can be simultaneously moved between the working and raised positions. In some embodiments, each working assembly of the plurality of working assemblies can be individually moved between the working and raised positions. In some embodiments, only select working assemblies of the plurality of working are moved between the working and raised positions.

[0062] As used herein, a height of a working assembly 120 is measured from the ground to a lowest part of the working assembly 120. In some embodiments, a height of the working assemblies 120 in the raised position can be greater than or equal to 0.05 meters, 0.25 meters, 0.5 meters, 0.7 meters, 0.7 meters, or 1.00 meters, or can be an amount falling within a range between any of the foregoing above the ground surface.

[0063] In various embodiments, the working assemblies 120 can form an angle with the ground surface when in the raised position. A plane of the ground surface can be defined by contact points of at least three vehicle ground-engaging rotatable members with the ground surface. A plane of a working assembly can be defined by points of the working assembly ground-engaging members that would first contact the ground surface when the working assembly is lowered down to the ground surface. As used herein, the angle formed between the working assembly and the ground surface is the acute angle formed by a line normal to the plane of the ground surface and a line normal to the plane of the working assembly. In some embodiments, the angle in the raised position between the ground-working assemblies and the ground can be greater than or equal to 0 degrees, 20 degrees, 40 degrees, 60 degrees, 80 degrees, 100 degrees, or 120 degrees, or can be an amount falling within a range between any of the foregoing.

[0064] In various embodiments, the ground-working machine 100 has a smaller overall width when the working assemblies in the raised position than when the working assemblies are in the working position. In various embodiments, the working assemblies are placed in the raised position for the purpose of transporting, shipping, or storing the ground-working machine 100 when the working assemblies are not mowing or otherwise performing their work. In some situations, one or more of the working assemblies can be in the raised position while one or more of the working assemblies can be in the working position.

[0065] Longitudinal and Lateral Axes (FIG. 3)

[0066] Referring now to FIG. 3, a top view of the ground-working machine of FIG. 1 is shown in accordance with various embodiments herein. The ground-working machine 100 can have a longitudinal axis 334. In various embodiments, the longitudinal axis is located at a lateral center of the vehicle 110. In various embodiments, the working assemblies 120 are distributed symmetrically about longitudinal axis 334. In various embodiments, a first working assembly 120 of the plurality of working assemblies can be disposed to the left of a lateral center of the vehicle 110 and a second working assembly 120 of the plurality of working assemblies can disposed to the right of a lateral center of the vehicle 110. In the example of FIG. 3, one working assembly 120 is distributed to the left of longitudinal axis 334, one working assembly 120 is distributed to the right of longitudinal axis 334, and one working assembly 120 is centered about longitudinal axis 334. In some embodiments, the working assemblies are not distributed symmetrically about longitudinal axis 334.

[0067] In various embodiments, the vehicle ground -engaging rotatable members 112 are distributed symmetrically about longitudinal axis 334. In the example of FIG. 3, two vehicle ground-engaging rotatable members 112 are distributed to the left of longitudinal axis 334 and two vehicle ground-engaging rotatable members 112 are distributed to the right of longitudinal axis 334.

[0068] The ground-working machine 100 can have a lateral axis 336. In various embodiments, lateral axis 336 is located at a longitudinal center of the vehicle 110. In various embodiments, the working assemblies 120 are distributed about lateral axis 336. In the example of FIG. 3, one working assembly 120 is distributed in front of lateral axis 336 and two working assemblies 120 are distributed to somewhat in front of and somewhat behind lateral axis 336. The front 140 of the vehicle 110 is in the direction that the operator seat 114 is facing and is in the direction of most typical forward travel from the operator seat 114. In the example of FIG. 3, the frontmost working assembly 120 is distributed at or in front of a front set of vehicle groundengaging rotatable members 112 and the two lateral working assemblies 120 are distributed between the front set vehicle ground-engaging rotatable members 112 and a rear set of vehicle ground-engaging rotatable members 112.

[0069] In various embodiments, the vehicle ground -engaging rotatable members 112 are distributed about lateral axis 336 In the example of FIG. 3, two vehicle groundengaging rotatable members 112 are distributed in front of the lateral axis 336 and two vehicle ground-engaging rotatable members 112 are distributed behind the lateral axis 336. Working Assembly

[0070] Referring now to FIG. 4, a perspective view of a working assembly is shown in accordance with various embodiments herein. As seen in FIG. 4, the working assembly 120 includes a carrier frame 436 with two or more ground-engaging rotatable members 121 connected to the carrier frame. In the embodiment of FIG. 4, the working assembly 120 has two front rotatable members and a rear rotatable member, that take the form of wheels. In another arrangements, the working assembly

[0071] 120 can include any suitable number or configuration of wheels and / or rollers. In an embodiment, one wheel or roller may be attached at each of the comers of the carrier frame. In another arrangement, the working assembly can include a front elongated roller and a rear elongated roller disposed at each side of the carrier frame. Other numbers and configurations of working assembly ground-engaging rotatable members

[0072] 121 are conceivable to those skilled in the art.

[0073] The working assembly can have a ground-working unit 435 connected to the carrier frame 436. In the example of FIG. 4, the working unit 435 is configured as a rotary ground cutting assembly having a housing 438, a blade or blades (not shown) that rotates around a substantially vertical axis within the housing 438. In alternative embodiments, the working assembly 120 can incorporate a reel cutting unit, a disc cutting unit, a flail cutting unit, or another type of cutting unit. In further embodiments, the working assembly 120 can be configured for spraying, debris collection, raking, or aerating, or the like.

[0074] In various embodiments, the working assembly 120 can include a connector handle 442, which can be configured to couple with one or more connection assemblies (not shown in this view), such as one of the connection assemblies 122 depicted by FIGS. 1-3. In various embodiments, one or more brackets 440 are configured to attach the connector handle 442 to the working assembly.

[0075] The working assembly typically includes many structures that are not shown in FIG. 4. For example, in various embodiments, the working assembly includes a blade mounting and drive system in an aperture of the housing 438 of the working unit 435. In various embodiments, the working assembly may also include fluid power connections to the blade mounting and drive system and mechanisms for adjusting the height of the working unit. Electric Motor Configurations (FIGS. 5-6)

[0076] As described above, the ground-working machine 100 can include a vehicle 110 having a plurality of vehicle ground-engaging rotatable members 112 configured to contact a ground surface. In various embodiments, the ground-working machine can include one or more electric motors configured to drive one or more of the plurality of vehicle ground-engaging rotatable members. An electric motor as defined herein is an electrical machine that converts electrical energy into mechanical energy. Types of electric motors can include AC motors, DC motors, induction motors, or the like. In alternative embodiments, ground-engaging rotatable members can be driven by other suitable means such as hydraulic motors, mechanical transmissions connected to mechanical axles via drive shafts, or the like.

[0077] In various embodiments, the ground-working machine can include a control system in communication with the one or more electric motors. In various embodiments, each electric motor is configured to communicate directly with a central machine controller. Alternatively, each electric motor operatively connected to its own traction controller that communicates with the machine controller.

[0078] In an embodiment, each electric motor is in communication with its respective traction controller. The electric motor is configured to transmit information to the traction controller. The information can include a torque value output indicating an applied torque. The applied torque corresponds to the torque applied by the electric motor to drive one or more of the plurality of vehicle ground-engaging rotatable members. Each traction controller can send information, including the torque value output to a machine controller. The machine controller is configured as the central control system for the ground-working machine and can process information from various systems. The machine controller is further configured to send instructions to each traction controller to set the torque output for its associated electric motor. The ground-working machine can have various configurations of ground engaging rotatable members as described in detail below.

[0079] Referring now to FIG. 5, a schematic view of a portion of a ground-working machine is shown in accordance with various embodiments herein. The groundworking machine can include a vehicle having a plurality of vehicle ground-engaging rotatable members 112. In the example of FIG. 5, the ground-working machine can include first electric motor 548 configured to drive a first axle 544 operably connected to a first rotatable member RMi and a second rotatable member RM2 of the plurality of vehicle ground-engaging rotatable members 112. The ground-working machine can further include a second electric motor 549 configured to drive a second axle 546 operably connected to a third rotatable member RM3 and a fourth rotatable member RM4 of the plurality of vehicle ground-engaging rotatable members 112.

[0080] In various embodiments, the first electric motor 548 is in communication with a first traction controller 550. In various embodiments, the second electric motor 549 is in communication with a second traction controller 551. The first traction controller 550 and the second traction controller 551 are in communication with the machine controller 552. In various embodiments, the machine controller 552 is configured to receive a first torque value output indicating first applied torque corresponding to the torque applied by the first electric motor 548 to the first rotatable member RMi and the second rotatable member RM2 via the first axle 544. In various embodiments, the machine controller 552 is configured to receive a second torque value output indicating second applied torque corresponding to the torque applied by the second electric motor 549 to the third rotatable member RM3 and the fourth rotatable member RM4 via the second axle 546.

[0081] In various embodiments, the first axle 544 and the second axle 546 can be mechanical transaxles. A transaxle, as defined herein, is a type of transmission used in many front-wheel -drive and some rear- wheel -drive vehicles. It combines the functions of a transmission and a differential into a single integrated unit. The transaxle houses the gears for changing the speed of the vehicle (transmission) and the gears that allow the wheels to rotate at different speeds (differential) in one assembly. In various embodiments, the first axle 544 and the second axle 546 can be any suitable type of axle such as axles with open differential, axles with limited slip differential, etc.

[0082] In various embodiments, all the vehicle ground-engaging rotatable members 112 are driven by electric motors, such as shown in FIG. 5 (e.g., all-wheel drive). Alternatively, the first and second rotatable members RM,. RM2 are driven by the first electric motor while the third and fourth rotatable members, RM3, RM4 are not driven (e.g., front wheel drive). Alternatively, the third and fourth rotatable members RM3, RM4 are driven by the first electric motor while the first and second rotatable members, RMi, RM2 are not driven (e g., rear wheel drive).

[0083] Referring now to FIG. 6, a schematic view of a portion of a ground-working machine is shown in accordance with various embodiments herein. The ground- working machine can include a vehicle having a plurality of vehicle ground-engaging rotatable members 112. In the example of FIG. 6, the vehicle has three groundengaging rotatable members 112, all of which are driven by their own electric motors. Rather than being connected to the electric motor via a mechanical transaxle, each of the ground-engaging rotatable members, each of the three ground-engaging rotatable members 112 may have its own in- wheel motor. An in -wheel motor is a type of EV (electric vehicle) drive system in which electric motors are installed at each of the driving wheels to directly power the wheels. In alternate embodiments, the vehicle may have fewer or greater than three individually driven ground-engaging rotatable members 112.

[0084] In the example of FIG. 6, the second ground-engaging rotatable member RM2 and third ground-engaging rotatable member RM3 are configured to be in the front 140 of the vehicle while the first ground-engaging rotatable member RMi is configured to be in the back of the vehicle. Alternatively, the second ground-engaging rotatable member RM2 and third ground-engaging rotatable member RM3 are configured to be in the back of the vehicle while the first ground-engaging rotatable member RMi is configured to be in the front 140 of the vehicle.

[0085] In the example of FIG. 6, the first electric motor 548 is configured to drive the first ground-engaging rotatable member RMi, the second electric motor 549 is configured to drive the second ground-engaging rotatable member RM2, and the third electric motor 662 is configured to drive the third ground-engaging rotatable member RM3 In various embodiments, the first electric motor 548 is in communication with a first traction controller 550, the second electric motor 549 in in communication with a second traction controller 551, and the third electric motor 662 in in communication with a third traction controller 664.

[0086] The first traction controller 550, second traction controller 551, and third traction controller 664 are in communication with the machine controller 52. In various embodiments, the machine controller 552 is configured to receive a first torque value output indicating a first applied torque corresponding to the torque applied by the first electric motor 548 to the first rotatable member RMi, a second torque value output indicating a second applied torque corresponding to the torque applied by the second electric motor 549 to the second rotatable member RM2, and a third torque value output indicating a third applied torque corresponding to the torque applied by the third electric motor 662 to the third rotatable member RM It should be noted that any suitable number and configurations of groundengaging rotatable members can be used. In an embodiment, the ground-working machine may have four or more individually drive ground-engaging rotatable members. In an embodiment, the ground-working machine may have two individually driven ground-engaging rotatable members in the front and two ground-engaging rotatable members sharing a common axle in the back.

[0087] Connection Assemblies

[0088] Referring now to FIGS. 7 and 8, a connection assembly is shown in accordance with various embodiments herein. The connection assembly 122 can include a connector handle 442, a connector arm 746, and a fluid power actuator 748. In various embodiments, the connection assembly 122 is configured to connect a working assembly 120 to the vehicle 110 of ground-working machine 100 such that the working assembly can be driven by the vehicle. In various embodiments, the connection assembly is configured to raise and lower the working assembly between a raised position and a working position and to apply a counterbalance pressure to the working assembly using the fluid power actuator 748. In various embodiments, the connection assembly 122 has a first end attached to a working assembly 120 and a second end attached to the vehicle 110. In some embodiments, the connection assembly 122 can include two or more fluid power actuators 748. In some embodiments, a working assembly can include two or more connection assemblies with each connection assembly having its own connector arm 746 and fluid power actuator 748.

[0089] In the embodiment of FIGS. 7 and 8, the working assembly 120 is attached to connector handle 442 with brackets 440. While not visible in FIGS. 7-8, the working assembly 120 can include an additional bracket or pair of brackets at the other end of connector handle 442. The connector handle 442 spans a top surface of the working assembly 120 and each end of the connector handle 442attaches to brackets 440 or another suitable connection structure.

[0090] As depicted by FIG. 7, a center portion of the connector handle 442 can connect to a first end of a connector arm 746 at connection hub 744. In various embodiments, the connection hub 744 can be configured to allow side-to-side rotation (rotation about an axis parallel to longitudinal axis 334) of the working assembly 120 with respect to the ground surface. In various embodiments, the connection hub 744 can be configured to allow fore / aft rotation (rotation about an axis parallel to lateral axis 336) of the working assembly 120 with respect to the ground surface. In various embodiments, connection hub 744 can be configured to allow the working assembly 120 to rotate about a vertical axis of the connection hub. Such rotation further enables the working assemblies 120 to follow uneven terrain independently of vehicle 110 while being driven by the vehicle.

[0091] In various embodiments, the connector arm 746 can connect to a linear actuator, such as fluid power actuator 748, and the vehicle 110 at a second end portion. In various embodiments, fluid power actuator 748 is configured to connect to the connector arm 746 at a first end and to the vehicle 110 at a second end. In the embodiment of FIGS. 7 and 8, the fluid power actuator 748 is configured as a hydraulic cylinder, but other fluid power actuators and other actuators are conceivable such as a pneumatic cylinders, linear actuators, screw type electric actuators, or the like. In addition, other types of linear actuators can be used in place of the fluid power actuator 748 in various embodiments, such as screw actuators or piezoelectric actuators.

[0092] In various embodiments, the fluid power actuator 748 can be operatively connected to a hydraulic system 124 of the ground-working machine 100. In various embodiments, the hydraulic system 124 is configured to control the fluid power actuator 748. In some embodiments, the hydraulic system 124 can induce a retraction or extension of the fluid power actuator, resulting in a corresponding raising or lowering of the working assembly between the working position and the raised position via connector arm 746. In the embodiment of FIGS. 7-8, a retraction of the fluid power actuator 748 raises working assembly 120 and an extension of the fluid power actuator 748 lowers working assembly 120. In an alternate configuration, extension of the fluid power actuator 748 raises the working assembly 120 and retraction of the fluid power actuator 748 lowers working assembly 120. In some embodiments, the hydraulic system can induce the fluid power actuator to offset at least part of the weight of the working assembly, transferring weight from the working assembly ground-engaging rotatable members 121 to the vehicle groundengaging rotatable members 112. The hydraulic system is described in further detail below. In some embodiments, the hydraulic system can induce the fluid power actuator to place downward pressure on the working assembly, transferring weight from the vehicle ground-engaging rotatable members 112 to the working assembly ground-engaging rotatable members 121. The hydraulic system is described in further detail below.

[0093] Hydraulic System

[0094] Referring now to FIG. 9, a schematic view of a hydraulic system for a groundworking machine is shown in accordance with various embodiments herein. It should be noted that the hydraulic system 124 depicted by FIG. 9 is simplified for explanatory purposes and the ground-working machine 100 can include additional hydraulic components such as valves, pumps, and the like. The hydraulic system 124 can be in communication with the machine controller 552. The hydraulic system can include a plurality of lift manifolds 952, each lift manifold having one or more valves including a counterbalance valve 954.. In various embodiments, the hydraulic system is configured to be disposed in the vehicle 110 of ground-working machine 100 such as in a lift block manifold within the vehicle.

[0095] The hydraulic system depicted by the example of FIG. 9 is configured for a ground-working machine 100 having five working assemblies 120. The exemplary hydraulic system has five lift manifolds 952 (LM i, LM2. .. LM5) and five counterbalance valves 954 (CBi, CB2. .. CB5) operatively connected to five fluid power actuators 748 (Fi, F2... F5) where each fluid power actuator is operatively connected to a connection assembly 122 connecting a working assembly 120 to the vehicle 110. In alternate configurations, a working assembly can be connected to two or more fluid power actuators. Similar configurations are possible for ground-working machines having different numbers of working units. For instance, a ground-working machine with seven working assemblies can have a hydraulic system with seven lift manifolds 952 (LMi, LM2...LM7) and seven counterbalance valves (CBi, CB2...CB7) operatively connected to seven fluid power actuators (Fi, F2.. . F7).

[0096] In various embodiments, hydraulic system 124 includes one or more lift manifolds operatively connected to machine controller 52. Each lift manifold can be operatively connected to its respective fluid power actuator(s) 748. The lift manifold 952 can include one or more solenoid control valves or the like. In various embodiments, when a lift switch on the operator control panel is activated, each lift manifold 952 is configured to apply a lift pressure to its respective working assembly 120 to move the connection assembly to a raised position not contacting the ground surface. When the ground-working machine 100 is in the working position (as depicted by FIG. 2) each working assembly 120 is substantially self-supporting on the ground and rolls over the ground on working assembly ground-engaging rotatable members 121. When the ground -working machine 100 is operating in the working position, the machine controller 552 is configured to control each lift manifold 952 to permit hydraulic fluid to flow freely though its respective fluid power actuator(s) 748 placing the fluid power actuators in a float mode. In doing so, the machine controller 552 permits the piston rod of each fluid power actuator 748 to move freely back and forth within each cylinder as the working assemblies 120 traverse the ground surface. This in turn allows each working assembly to follow the terrain of the ground.

[0097] To move the working assemblies 120 from the working position (depicted by FIG. 2) to the raised position (depicted by FIG. 3), when a lift switch on the operator control panel is activated, the machine controller 552 is configured to signal each lift manifold 952 to open and for a pump (not shown) to supply pressurized hydraulic fluid to its respective plurality of fluid power actuator(s) 748. In various embodiments, the hydraulic fluid pushes against the pistons of each of the fluid power actuators causing them to retract and lift their respective working assembly 120 to the raised position.

[0098] In turn, to lower the working assemblies 120 from the raised position back to the working position, when a switch on the operator control panel is activated, the machine controller 552 can signal each lift manifold 952 to open and to control the pump to allow the hydraulic fluid to drain back out of its respective fluid power actuator(s) 748 thereby permitting the working assemblies 120 to lower from their raised positions to their working positions. In some embodiments, the working assemblies 120 are lowered from their raised positions to their working positions by the force of gravity. Additionally or alternatively, the working assemblies 120 are lowered from their raised positions to their working positions using mechanical power, such as from the fluid power actuators 748. In some embodiments, multiple lift valves are provided and are configured to raise and lower groups of working assemblies or single working assemblies.

[0099] In various embodiments, each lift manifold 952 can include a counterbalance valve 954. Each counterbalance valve 954 can be operatively connected to machine controller 552 and to a fluid power actuator 748 of the plurality of fluid power actuators (Fi, F2.. . F5). Each counterbalance valve 954 can be configured as a solenoid control valve, or the like. In various embodiments, each counterbalance valve 954 is configured to apply a counterbalance pressure or back pressure to its respective working assembly 120 via the fluid power actuator 748. The counterbalance pressure causes a lift force to be applied to each working assembly 120, transferring at least a portion of the weight of the working assembly to the vehicle 110 while the working assembly ground-engaging rotatable members 121 remain in contact with the ground surface.

[0100] The counterbalance pressure applied by each counterbalance valve 954 can be a function of a counterbalance value determined by machine controller 552. In various embodiments, each counterbalance valve 954 is configured to apply a counterbalance pressure dynamically to its respective working assembly based on one or more inputs received from machine controller 552. Each counterbalance valve 954 can be operatively connected to a connection assembly 122 and each connection assembly can apply a counterbalance pressure of the determined counterbalance value to its respective working assembly 120.

[0101] In various embodiments, the counterbalance valves 954 apply the counterbalance pressure while the ground-working machine 100 is in the working position. When in the working position without a counterbalance pressure applied, the working assembly ground-engaging rotatable members 121 transfer most of their weight directly to the ground. In some cases, this can adversely affect the traction of the vehicle 110. Accordingly, there are times when it would be desirable to transfer at least a portion of the weight of the working assemblies 120 back to the vehicle to put more downforce on the vehicle ground-engaging rotatable members 112 thereby increasing their traction. To accomplish this, each connection assembly 122 is configured to apply a counterbalance pressure to its respective working assembly 120. The counterbalance pressure applies an upward force to each working assembly 120 and shifts weight from the working assembly ground-engaging rotatable members 121 to the vehicle ground-engaging rotatable members 112. The amount of counterbalance pressure applied to each working assembly is determined by the counterbalance system using inputs which is described in detail below.

[0102] Counterbalance System (FIG. 10)

[0103] Referring now to FIG. 10, a schematic view of a counterbalance system is shown in accordance with various embodiments herein. In various embodiments, the counterbalance system includes a control system (such as machine controller 552). The control system can be configured to receive one or more inputs and based on the one or more inputs, determine an appropriate counterbalance pressure for each of the one or more working assemblies 120, and dynamically apply a counterbalance pressure or change an already-applied counterbalance pressure to each of the working assemblies 120 via its respective connection assembly 122. The inputs and outputs to the control system will now be described.

[0104] Traction Controller! s)

[0105] In various embodiments, the ground-working machine can include one or more electric motors configured to drive one or more of the plurality of vehicle ground-engaging rotatable members. Each electric motor is in communication with its respective traction controller. The electric motor is configured to send information to the traction controller. The information can include a torque value output indicating an applied torque. The applied torque corresponds to the torque applied by the electric motor to drive one or more of the plurality of vehicle ground-engaging rotatable members.

[0106] Alternatively, each electric motor outputs the current being applied to its associated ground engaging rotatable member(s) to its respective traction controller. The current output for each electric motor can be correlated to the torque applied to associated ground engaging rotatable member(s) and the output current can be used as a proxy for torque by the machine controller. Alternatively, the machine controller can be configured to convert the output current to applied torque.

[0107] Based on at least the torque value output sent by each traction controller, the machine controller is further configured to transmit commands back to each traction controller. In particular, the machine controller is configured to set the torque (or current) applied by each traction controller to its associated ground engaging rotatable member(s).

[0108] In various embodiments, based on the torque value or torque values received from the traction controller(s), the machine controller is configured to determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to each of the one or more working assemblies via its connection assembly. If a determination is made to apply or change a counterbalance pressure at a particular working assembly, the machine controller is configured to determine a counterbalance value based on the torque value or torque values, throttle position, and, in some cases, a location of the particular working assembly with respect to the vehicle. The machine controller 552 is configured to apply a counterbalance pressure of the determined counterbalance value via a connection assembly 122 to each particular working assembly 120 for which a determination was made to apply or change a counterbalance pressure. In various embodiments, the working assembly ground-engaging rotatable members 121 of each working assembly remain in contact with a ground surface while the determined counterbalance pressure is applied.

[0109] In various embodiments, the counterbalance pressure applied to each working assembly 120 changes dynamically as a function of one or more factors including the torque value. The control system is configured to read the torque value(s) from the traction controller(s) and adaptively output counterbalance values continuously or at a set time interval. In some embodiments, the set time interval can be greater than or equal to 0.01, 0.02, 0.02, 0.03, or 0.04 seconds. In some embodiments, the set time interval can be less than or equal to 0.10, 0.08, 0.07, 0.06, or 0.04 seconds. In some embodiments, the set time interval can fall within a range of 0.01 to 0.10 seconds, or 0.02 to 0.08 seconds, or 0.02 to 0.07 seconds, or 0.03 to 0.06 seconds, or can be about 0.04 seconds.

[0110] In alternative embodiments, the control system can take a rolling average of values from the traction controller(s) as an input to the counterbalance algorithm. In some embodiments, the rolling average can be taken over greater than or equal to two, three, four, or five torque values. In some embodiments, the rolling average can be taken over less than or equal to ten, eight, seven, or five torque values. In some embodiments, the rolling average can be taken over a range of two to ten torque values, or three to eight torque values, or four to seven torque values, or can be about five torque values.

[0111] In various embodiments, the counterbalance pressure applied to a given working assembly 120 changes dynamically with the torque. In various embodiments, when the torque value for each of the vehicle ground engaging rotatable members falls within an expected torque value range, the counterbalance pressure set for the working assembly will be a baseline counterbalance pressure. In some embodiments, the baseline counterbalance can be zero. Alternatively, the baseline counterbalance pressure can be above zero. The change in torque is a dynamic input to which the control system responds. For instance, the counterbalance pressure applied to the one or more working assemblies increases as the torque output by one or more traction controllers increases above a maximum expected torque value (or decreases below a minimum expected torque value) until the maximum allowable counterbalance pressure has been achieved (or until the torque value(s) fall within the expected torque value range). Once the maximum allowable counterbalance value for a particular working assembly has been reached, higher torque values will not further increase the counterbalance value. In some embodiments, the maximum allowable counterbalance pressure corresponds to the counterbalance pressure at which the weight of the working assembly 120 has substantially all be transferred to the vehicle 110, but the working assembly ground-engaging rotatable members 121 remain engaged with the ground surface.

[0112] Slope Sensor

[0113] In various embodiments, the control system is configured to receive an input from a slope sensor. A slope sensor defined herein is an instrument used for measuring angles of slope, elevation, or depression of an object with respect to gravity's direction. The slope sensor can take the form of an accelerometer, a liquid capacitive inclinometer, electrolytic tilt sensor, gas bubble in liquid sensor, pendulum, or the like. In some embodiments the slope sensor is configured to measure the slope along one, two, three, or four or more axes.

[0114] In various embodiments, the slope sensed by the slope sensor can be reflective of the attitude of the ground-working machine with respect to a ground surface. In various embodiments, the slope sensor can be disposed on or within the vehicle 110 of the ground-working machine to determine the attitude of vehicle relative to a substantially horizontally reference plane.

[0115] In various embodiments, the machine controller receives one or more slope values from the slope sensor. Each slope value can indicate a slope of the vehicle 110 with respect to a horizontal reference plane. In various embodiments, the machine controller is configured to receive a lateral slope value from the slope sensor 1162. Lateral slope value can indicate a slope of the vehicle along lateral axis with respect to a horizontal reference plane. In various embodiments, the machine controller is configured to receive a longitudinal slope value from the slope sensor. The longitudinal slope value can indicate a slope of the vehicle along longitudinal axis 334 with respect to a horizontal reference plane. In an exemplary embodiment, the machine controller is configured to receive a both longitudinal slope value and a lateral slope value from the slope sensor. It should be noted that the machine controller can be configured to receive any number of slope values along any number of axes from the slope sensor. In some embodiments, the number of slope values received by the machine controller can be greater than or equal to one, two, three, or four or more slope values. In most instances where the description references the input of a slope value, the system could also have two or more slope values as inputs.

[0116] In various embodiments, based on the slope value or slope values received from the slope sensor, the machine controller is configured to determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to each of the working assemblies via its connection assembly. If a determination is made to apply or change a counterbalance pressure at a particular working assembly, the machine controller is configured to determine a counterbalance value based on the slope value or slope values and a location of the particular working assembly with respect to the vehicle. The machine controller is configured to apply a counterbalance pressure of the determined counterbalance value via a connection assembly to each particular working assembly for which a determination was made to apply or change a counterbalance pressure. In various embodiments, the working assembly groundengaging rotatable members of each working assembly remain in contact with a ground surface while the determined counterbalance pressure is applied.

[0117] The slope of the ground-working machine with respect to a ground surface can also affect the torque output for each of the electric motors. Due to the effects of gravity, the torque output for each traction motor is expected to increase for a given ground speed as the incline of the vehicle increases. Conversely, torque values are generally expected to decrease when the ground-working machine encounters a negative slope or decline in the terrain. Due to the increased tractive effort to drive the vehicle uphill, the machine controller can be configured to increase the counterbalance pressure on one or more working assemblies to increase the traction of the vehicle ground engaging rotatable members as the incline of the vehicle increases.

[0118] Issues with traction can also occur when a ground-working machine laterally traverses an incline. For example, when traversing an incline such that the rotatable members on the right side of the vehicle are disposed above the rotatable members on the left side of the vehicle, the right-side rotatable members are expected to experience reduced traction with respect to the ground surface. To reduce the likelihood of the right-side rotatable members slipping, the machine controller can be configured to increase the counterbalance pressure on one or more working assemblies. In some embodiments, the machine controller can be configured to increase the counterbalance pressure on all of the working assemblies. Alternatively, the machine controller can be configured to increase the counterbalance pressure on only working assemblies disposed to the right side of the vehicle.

[0119] Further, when traversing the lateral incline such that the right-side rotatable members are disposed above the left side rotatable members, the ground-working machine might make a 180° turn such that the left-side rotatable members are disposed above the right-side rotatable members. In such a scenario, it could be advantageous to have dynamic counterbalance shift counterbalance pressure from right to left as the turn is made based. For instance, the machine controller can go from applying increased counterbalance pressure to the working assemblies disposed to the right side of the vehicle to applying increased counterbalance pressure to the working assemblies disposed to the left side of the vehicle.

[0120] Throttle Position Sensor

[0121] In various embodiments, the ground-working machine includes a throttle which can take the form of a foot pedal, shifting lever, or the like. As the user actuates the throttle (e g., by depressing a foot pedal) the throttle position sensor changes its output to indicate the throttle position which corresponds to the user’s desired ground speed. In various embodiments, the user can request a speed by actuating a second foot pedal, shifting a lever into a reverse position, or the like. In various embodiments, the throttle position sensor is in communication with the machine controller, such as the machine controller is configured to receive a throttle position value for the throttle sensor.

[0122] In one embodiment, the throttle position sensor provides an output measured in volts. In various embodiments, the throttle position is directly related to the ground speed of the vehicle (e g , a throttle position of 2 volts correlates to a desired ground speed of 2 MPH). In alternate embodiments, the machine controller can directly receive the actual ground speed of the vehicle from one or more of an accelerometer, GPS, position sensor, or the like. The ground speed of the ground-working machine can also affect the torque output for each of the traction mowers. It is generally expected that the torque output for each traction motor will increase for a given set of environmental conditions as the ground speed of the vehicle increases. Due to the increased tractive effort to drive the vehicle at higher ground speeds, the machine controller can be configured to increase the counterbalance pressure on one or more working assemblies to increase the traction of the vehicle ground engaging rotatable members as the ground speed of the vehicle increases.

[0123] In various embodiments, the machine controller is further configured to receive signals from the braking system on whether regenerative braking is activated. Regenerative braking, as defined herein, is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In an embodiment, the controller is configured to determine that regenerative braking as activated when receiving a signal from the braking system indicating that the throttle pedal is actuated to decelerate the ground-working machine. In an embodiment, the machine controller is configured to determine that regenerative braking as activated when the there is a mismatch between the throttle position sensor output and the ground speed (e.g., the vehicle is traveling at a ground speed that is higher than the throttle position). In an embodiment, the machine controller is configured to determine that regenerative braking is activated when one or more inputs (e.g., a position sensor or accelerometer) indicates that the vehicle is decelerating.

[0124] Connection Assemblies

[0125] In various embodiments, the machine controller is configured to receive a signal from each connection assembly indicating the position of it associated working assembly. For instance, each connection assembly can relay to the machine controller whether the associated working assembly is in its working position (as depicted by FIG. 1) or in its raised position (as depicted by FIG. 2). In various embodiments, the machine controller is only configured to increase the counterbalance pressure to a given working assembly if its associated connection assembly indicates that the working assembly is in its working position.

[0126] Downward Counterbalance Pressure In some embodiments, the control system can be configured to control the connection assemblies to apply both upward and downward counterbalance pressures on the working assemblies, as opposed to just upward pressure. In such embodiments, a positive counterbalance pressure to be applied to working assemblies disposed uphill from the vehicle and a negative counterbalance pressure can be applied on working assemblies disposed downhill from the vehicle.

[0127] Exemplary Counterbalance System Scenarios (FIG. 11)

[0128] Referring now to FIG. 11, a schematic view of a ground-working machine on a ground surface is shown in accordance with various embodiments herein. The ground-working machine 100 can have some of or all the features of the groundworking machines described previously but is drawn schematically for clarity. The ground-working machine 100 includes a vehicle 110 and three working assemblies 120 (labeled Wi.. . . W3). As illustrated in other FIGS., but not in FIG. 11, each working assembly 120 can have a working unit 435 and a plurality of working assembly ground-engaging rotatable members 121 configured to contact the ground surface. Each working assembly 120 can be attached to the vehicle with a connection assembly 122. The ground-working machine may further include a throttle position sensor 1160 and a slope sensor 1162.

[0129] FIG. 11 shows a ground-working machine with three working assemblies in a one-two configuration, meaning that one is in a front row of working assemblies and two are in a rear row of working assemblies. Although the present example describes a ground-working machine with three working assemblies in a one-two configuration, the principles described herein apply to ground-working machines having other numbers of working assemblies (e g., a single working assembly or two or more working assemblies) or other configurations of working assemblies.

[0130] The ground working assembly of FIG. 11 includes four vehicle groundengaging rotatable members 112 (labeled RMi .... RM4) and three electric motors 548 (labeled EMi .... EM3). The ground-working machine 100 includes a first electric motor EMi configured to drive a first axle 544 operably connected to a first rotatable member RMi and a second rotatable member RM2 of the plurality of vehicle groundengaging rotatable members 112. The ground-working machine 100 further includes a second electric motor EM2 configured to drive the third ground-engaging rotatable member RM3 and a third electric motor EM3 configured to drive the fourth groundengaging rotatable member RM4.

[0131] In various embodiments, the first electric motor EMi is in communication with a first traction controller TCi and first traction controller TCi is in communication with the machine controller 552. In various embodiments, the machine controller 552 is configured to receive a first torque value output indicating first applied torque corresponding to the torque applied by the first electric motor 548 to the first rotatable member RMi and the second rotatable member RM2 via the first axle 544.

[0132] In various embodiments, the second electric motor EM2 is in communication with a second traction controller TC2 and the third electric motor EM3 is in communication with a third traction controller TC3. The second traction controller TC2 and the third traction controller TC3 are in communication with machine controller 552. In various embodiments, the machine controller 552 is configured to receive a second torque value output indicating a second applied torque corresponding to the torque applied by the second electric motor EM2 to the third rotatable member RM3, and a third torque value output indicating a third applied torque corresponding to the torque applied by the third electric motor EM3 to the fourth rotatable member RM4.

[0133] In various embodiments, the machine controller is configured to, based each torque value, determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to each working assembly. If a determination is made to apply or change a counterbalance pressure at the first working assembly, the machine controller is further configured to determine each counterbalance value based on the received torque values. The machine controller is further configured to apply a counterbalance pressure of the determined counterbalance value via each first connection assembly to the respective working assembly for which a determination was made to apply or change a counterbalance pressure.

[0134] In various embodiments, the machine controller is configured to increase the counterbalance pressure applied to at least one of the working assemblies upon determining that a received torque value output is outside of an expected range of torque values. An expected range of torque values, as defined herein, is a range of torque values that a traction motor is expected to output over for a given set of operating conditions (e g., ground speed). Having a torque output lower than a minimum expected torque value for a set of operating conditions can indicate that the associated rotatable member has lost traction with the ground surface. Having a torque higher than a maximum expected torque value for a set of operating conditions can indicate that the associated rotatable member is at a heightened risk of losing traction with the ground surface. In various embodiments, the machine controller is configured to maintain or decrease the counterbalance pressure applied to the first working assembly upon determining that a received torque value output falls within the expected range of torque values.

[0135] In the example of FIG. 11 , the first working assembly W i is disposed at the longitudinal center of the vehicle in front of the first axle 544, the second working assembly W2 is disposed to the left of a longitudinal center of the vehicle, and the third working assembly W3 is disposed to the right of a longitudinal center of the vehicle. Scenarios of losing traction described below:

[0136] In the example of FIG. 11, upon sensing that the first torque value output, second torque value output, and third torque value output are all out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to any of the plurality of working assemblies. In an embodiment, the machine controller is configured to increase the counterbalance pressure applied to all of the working assemblies Wi, W2, W3. In various embodiments, the machine controller is configured to increase the counterbalance pressure until sensing that the first torque value output, second torque value output, and third torque value output are all above the lower torque threshold. In alternative embodiments, upon sensing that the first torque value output, second torque value output, and third torque value output are all out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to the two lateral working assemblies W2, W3. In alternative embodiments, upon sensing that the first torque value output, second torque value output, and third torque value output are all out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to the center working assembly Wi, or any other suitable combination of working assemblies.

[0137] In the example of FIG. 11, upon sensing that the first torque value output is out of the expected torque value range (which could indicate a loss of traction of either / both of rotatable members RMi and RM2), the machine controller is configured to increase the counterbalance pressure applied to all of the working assemblies W 1, W2, W3. In various embodiments, the machine controller is configured to increase the counterbalance pressure until sensing that the second torque value output is above the lower torque threshold. In alternative embodiments, upon sensing that the second torque value output is out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to the two lateral working assemblies W2, W3, or any other suitable combination of working assemblies.

[0138] In the example of FIG. 11, upon sensing that the second torque value output is out of the expected torque value range (for instance when a ground-working machine laterally traverses an incline such that the left-side rotatable members are disposed above the right-side rotatable members), the machine controller is configured to increase the counterbalance pressure applied only to working assembly W2. In various embodiments, the machine controller is configured to increase the counterbalance pressure until sensing that the second torque value output is above the lower torque threshold. In alternative embodiments, upon sensing that the second torque value output is out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to working assemblies W 1 and W2, or any other suitable combination of working assemblies.

[0139] In the example of FIG. 11, upon sensing that the third torque value output is out of the expected torque value range (for instance when a ground-working machine laterally traverses an incline such that the right-side rotatable members are disposed above the left-side rotatable members), the machine controller is configured to increase the counterbalance pressure applied only to working assembly W3. In various embodiments, the machine controller is configured to increase the counterbalance pressure until sensing that the second torque value output is above the lower torque threshold. In alternative embodiments, upon sensing that the third torque value output is out of the expected torque value range, the machine controller is configured to increase the counterbalance pressure applied to working assemblies Wi and W3, or any other suitable combination of working assemblies.

[0140] Expected Torque and Counterbalance (FIGS. 12-14)

[0141] Referring now to FIG. 12, a graph showing traction electric motor current vs. ground speed is shown in accordance with various embodiments herein. Typically, an electric motor outputs the current being applied to its associated ground engaging rotatable member) s) to its respective traction controller For the purpose of this analysis, it will be assumed that current is directly proportional to torque such that the machine controller is configured to convert current to torque or vis versa. Current can be expressed with the units Amps. Torque can be expressed with the units of footpounds. Further note, that the numerical values depicted in FIG. 12 are for exemplary purposes only and can vary based on many factors including, but not limited to the type / configuration of electric motor, the overall size / configuration of the groundworking machine, and environmental conditions. Further note that FIG. 12 shows example torque values as singular points. However, expected torque values for a given set of conditions can fall within a tolerance range of expected torque values depending on a number of factors including, but not limited to weather conditions, surface conditions, tire pressure, or the like.

[0142] In the example of FIG. 12, the ground speed is expressed in miles per hour and can be correlated to the output of the electric throttle position sensor (eTPS), which can be expressed with the units Volts in one example. In various embodiments, the ground-working machine includes a throttle which can take the form of a foot pedal, thumb lever, or the like. As the user actuates the throttle (e.g., by depressing a foot pedal) the throttle position sensor changes its output to indicate the throttle position which corresponds to the user’s desired ground speed. In one example, the throttle position sensor output can vary from -2 to 10, where 10 is maximum vehicle ground speed, 0 is neutral position (corresponding to zero torque output), and -2 is maximum reverse speed. In various embodiments, the user can request a reverse speed by actuating a second foot pedal, shifting a lever into a reverse position, or the like. In the embodiment of FIG. 12, the eTPS output correlates to the desired ground speed in miles per hour (e.g., an eTPS output of 2 Volts corresponds to a speed request of about 2 miles per hour) but many other relationships between ground speed and eTPS are possible.

[0143] In an embodiment, each traction controller can have an expected torque value for various conditions. The expected torque value corresponds to the expected amount of current required for an electric motor to drive its associated ground engaging rotatable member) s)) for a particular eTPS position. In various embodiments, the expected torque values are determined and stored by the machine controller. One way of determining the expected torque values is testing the ground- working machine in a variety of controlled conditions and storing the resulting torque values with the machine controller. Various modeling and machine learning approaches can also be implemented to determine the expected torque values. FIG. 12 shows the expected torque values for an electric motor in a variety of conditions including various ground speeds and levels of incline. Three example scenarios 1202, 1204, and 1206 at three different ground speeds are included. As detailed in the discussion of FIG. 10, the ground-working machine includes a machine controller that receives inputs indicating at least the ground speed and the incline of the ground- working machine. Using these inputs, the machine controller is configured to determine an expected output torque for each electric motor. The machine controller is further configured to receive the real time torque outputs for each electric motor from its associated traction controller and compare the real time torque values to the expected torque values for a given set of conditions.

[0144] Referring now to example scenario 1202, expected torque value range 1203 corresponds to the expected torque value outputs of a traction motor for a range of inclines at 2 mph between 0 and 20°. Datapoint ETFI corresponds to the expected torque value (motor current) for a traction motor to drive its associated ground engaging rotatable members) at a first speed (2 mph) in substantially flat conditions, datapoint ETn corresponds to the expected torque value for a traction motor to drive its associated ground engaging rotatable member(s) at the first speed up an incline of approximately 20°, and datapoint SPi shows the maximum expected torque value before the ground engaging rotatable member(s) are expected to lose traction (slip) with respect to the ground surface.

[0145] In the example of FIG. 12, datapoint ETn is the maximum expected output current (torque) for the given conditions (e.g., a ground speed of 2 mph and an incline of 20°). Upon receiving a real-time torque value that exceeds the maximum expected torque output (any torque value falling within counterbalance range denoted CB i), the machine controller is configured to increase the counterbalance pressure to one or more of the working assemblies. The counterbalance range as defined herein corresponds to any torque value falling between the maximum expected torque value (ETn) and the maximum possible torque (SPi) before loss of traction occurs. Increasing the counterbalance pressure to the working assemblies shifts some of the weight of the working assemblies to the vehicle. This increases the traction of the ground-engaging rotatable members and prevents the wheels from slipping. In some embodiments, the counterbalance pressure is increased to all the working assemblies Alternatively, the counterbalance pressure is increased to only the working assembly / assemblies closest to the ground engaging rotatable member or members that have torque values falling within the counterbalance range. Referring now to example scenario 1204, expected torque value to range 1205 corresponds to the expected torque value output of a traction motor for a range of inclines at 5 mph between 0 and 20°. Datapoint ETF2 corresponds to the expected torque value for a traction motor to drive its associated ground engaging rotatable member(s) at a second speed (5 mph) in substantially flat conditions, datapoint ET12 corresponds to the expected torque value for a traction motor to drive its associated ground engaging rotatable member(s) at the second speed up an incline of approximately 20°, and datapoint SP2 shows the expected maximum torque value output before the ground engaging rotatable member(s) are expected to lose traction (slip) with respect to the ground surface.

[0146] In the example of FIG. 12, datapoint ET12 is the maximum expected output current (torque) for the given conditions (e.g., a ground speed of 5 mph and an incline of 20°). Upon receiving a real-time torque value that exceeds the maximum expected torque output (any torque value falling within counterbalance range denoted CB2), the machine controller is configured to increase the counterbalance pressure to one or more of the working assemblies.

[0147] Referring now to example scenario 1206, expected torque value range 1207 corresponds to the expected torque output of a traction motor for a range of inclines at 10 mph between 0 and 20°. Datapoint ETFS corresponds to the expected torque value for a traction motor to drive its associated ground engaging rotatable member(s) at a third speed (10 mph) in substantially flat conditions, datapoint ET13 corresponds to the expected torque value for a traction motor to drive its associated ground engaging rotatable member(s) at the third speed up an incline of approximately 20°, and datapoint SP3 shows the expected maximum torque value output before the ground engaging rotatable member(s) are expected to lose traction (slip) with respect to the ground surface.

[0148] In the example of FIG. 12, datapoint ET13 is the maximum expected output current (torque) for the given conditions (e.g., a ground speed of 10 mph and an incline of 20°). Upon receiving a real-time torque value that exceeds the maximum expected torque output (any torque value falling within counterbalance range denoted CB3), the machine controller is configured to increase the counterbalance pressure to one or more of the working assemblies.

[0149] As depicted by FIG. 12, the expected torque values are generally expected to increase with both ground speed and incline. While not illustrated in FIG. 12, the expected torque values are generally expected to decrease when the ground-working machine encounters a negative slope or decline in the terrain. Many other factors can impact the expected torque value for a given electric motor including, but not limited to the type of ground surface, environmental conditions, turf height, and the condition of the ground- working machine and its ground engaging rotatable members.

[0150] In some embodiments, dynamic counterbalance can be used to restore traction to a ground engaging rotatable member after traction is lost. In various embodiments, the machine controller is configured to receive a first torque value that is above the maximum expected torque value for a given set of conditions (e g., for a set throttle position) followed by a second torque value indicating a rapid decrease in the torque applied by the first electric motor. In some cases, rapid decrease in torque / current applied by the electric motor can indicate that the ground engaging rotatable member(s) associated with a given electric motor have lost traction with the ground (slipped). Upon slipping, the ground engaging rotatable member is no longer driving the vehicle forward (or in reverse) and this will suddenly require significantly less effort to rotationally drive. Consequently, the controller will rapidly reduce the current to the electric motor to drive the rotatable member at the desired ground speed.

[0151] Upon receiving an indication of a slip condition, the machine controller is configured to increase the counterbalance pressure to one or more of the working assemblies. In some embodiments, the counterbalance pressure is increased to all of the working assemblies. Alternatively, the counterbalance pressure is increased to only the working assembly / assemblies closest to the ground engaging rotatable member or members that have lost traction. In various embodiments, the machine controller will continue to increase the counterbalance pressure until traction is restored (e.g., when the machine controller receives a torque value that is at or near the expected torque value) or until the counterbalance pressure reaches its maximum counterbalance value.

[0152] In various embodiments, a rapid decrease in torque as defined herein means a drop in motor current of at least 30% over the course of a time period of 10 seconds or less. In some embodiments, a rapid drop in current corresponds to a drop in current greater than or equal to 30 %, 40 %, 50 %, 60 %, 70 %, or 80 %, or can be an amount falling within a range between any of the foregoing. In some embodiments, the time period used for this determination of a rapid drop in current can be less than or equal to 10.0, 8.0, 6.0, 4.0, 2.0, or 0.5 seconds, or can be an amount falling within a range between any of the foregoing.

[0153] In some cases, the electric motor may experience a rapid decrease in torque that does not correspond to a loss of traction. For instance, if the vehicle starts going downhill, then torque / current will decrease rapidly. The downhill path will likely cause regenerative braking to be engaged to keep the speed of the vehicle consistent with the throttle position and under the maximum speed. In such embodiments, it is desirable for the machine controller to detect the change in torque, but not increase the counterbalance applied to the working assemblies. In various embodiments, the controller is configured to receive an input indicating that the ground-working machine is performing regenerative braking and to not increase the counterbalance applied to the working assemblies when regenerative braking is being performed.

[0154] FIGS. 13-14 provide exemplary scenarios to illustrate the concepts described in FIG. 12. Referring now to FIG. 13, a plot showing electric motor torque and incline of a ground-working machine over time is shown in accordance with various embodiments herein. Line 1314 depicts the electric motor torque over a given time period. Line 1316 depicts the incline of a ground-working machine over the given time period. At time 1300, the electric motor starts and reaches a steady state torque at time 1302. The torque remains steady until the ground-working machine encounters an incline at time 1304. The torque continues to increase with the grade of the incline. At time 1306, the torque value reaches the maximum expected torque value for the given conditions. Upon receiving a torque value that exceeds the maximum expected torque value, the machine controller starts to apply counterbalance to one or more working assemblies of the ground-working machine. At time 1306, the counterbalance starts to increase traction to the ground engaging rotatable members. This is achieved prior to reaching maximum torque value before the ground engaging rotatable member(s) start to slip 1310. At time 1308, a steady state at the increased level of counterbalance is reached and the electric motor outputs a steady torque below the expected slip point 1310.

[0155] Referring now to FIG. 14, a plot showing electric motor torque and incline of a ground-working machine over time is shown in accordance with various embodiments herein. Line 1414 depicts the electric motor torque over a given time period. Line 1416 depicts the incline of a ground-working machine over the given time period. At time 1400, the electric motor starts and reaches a steady state torque at time 1402. The torque remains steady until the ground-working machine encounters an incline at time 1404. The torque continues to increase with the grade of the incline. At time 1406, the torque value reaches the maximum expected torque value for the given conditions. Upon receiving a torque value that exceeds the maximum expected torque value, the machine controller starts to apply counterbalance to one or more working assemblies of the ground-working machine. However, in this scenario, the torque continues to increase rapidly (due to the user increasing the ground speed, a change in terrain, or the like) until it reaches the maximum torque value for before the ground engaging rotatable member(s) start to slip at time 1408. The machine controller detects the rapid decrease in torque between times 1408 and 1410 and interprets it as a slip condition. At time 1410, the machine controller increases the counterbalance applied to the working assemblies. Traction is restored to the ground engaging rotatable members and at time 1412, a steady state at the increased level of counterbalance is reached and the electric motor outputs a steady torque below the maximum expected torque value.

[0156] Methods of Applying Counterbalance

[0157] Many different methods are contemplated herein, including, but not limited to, methods of making, methods of using, and the like. Aspects of system / device operation described elsewhere herein can be performed as operations of one or more methods in accordance with various embodiments herein.

[0158] Referring now to FIG. 15, a method for operating a ground-working machine is shown in accordance with various embodiments herein. The ground-working machine can include a vehicle having at least one electric motor configured to drive a plurality of vehicle ground-engaging rotatable members and at least one working assembly. Each working assembly can be operatively connected to the vehicle by a connection assembly. Each connection assembly can be configured to apply a counterbalance pressure to the connected working assembly such that the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members.

[0159] In various embodiments, method 1500 can include step 1502, reading a torque value output In various embodiments, the torque value output can be read from the electric motor. In various embodiments, the torque value output is indicative of an applied torque, which is torque applied by the electric motor to drive the one or more of the plurality of vehicle ground-engaging rotatable members. In various embodiments, reading the torque value can include reading a first torque value from a first electric motor, a second torque value from a second electric motor, and each torque value from each additional electric motor.

[0160] In various embodiments, method 1500 can include step 1504 of determining whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly. In various embodiments, the counterbalance value determined for each working assembly is based at least on the torque value output received by the electric motor.

[0161] In various embodiments, method 1500 can include step 1506 of applying a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure. In various embodiments, the minimum counterbalance value and the maximum counterbalance value span a counterbalance range. In various embodiments, the cutting assembly ground-engaging rotatable members of each of the working assemblies remain in contact with a ground surface over the counterbalance range.

[0162] It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0163] It should also be noted that, as used in this specification and the appended claims, the phrase “configured” describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a particular configuration. The phrase "configured" can be used interchangeably with other similar phrases such as arranged and configured, constructed, and arranged, constructed, manufactured and arranged, and the like.

[0164] All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference. As used herein, the recitation of numerical ranges by endpoints shall include all numbers subsumed within that range (e.g., 2 to 8 includes 2.1, 2.8, 5.3, 7, etc.).

[0165] The headings used herein are provided for consistency with suggestions under 37 CFR 1.77 or otherwise to provide organizational cues. These headings shall not be viewed to limit or characterize the invention(s) set out in any claims that may issue from this disclosure. As an example, although the headings refer to a “Field,” such claims should not be limited by the language chosen under this heading to describe the so-called technical field. Further, a description of a technology in the “Background” is not an admission that technology is prior art to any invention(s) in this disclosure. Neither is the “Summary” to be considered as a characterization of the invention(s) set forth in issued claims.

[0166] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices. As such, aspects have been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope herein.

Claims

The Claims Are:

1. A ground-working machine comprising: a. a vehicle comprising: i. a plurality of vehicle ground-engaging rotatable members configured to contact a ground surface; ii. a first electric motor to drive one or more of the plurality of vehicle ground-engaging rotatable members; b. a first working assembly comprising a ground-working unit and a plurality of working assembly ground-engaging rotatable members configured to contact the ground surface; c. a first connection assembly, wherein the first connection assembly attaches the first working assembly to the vehicle, the first connection assembly configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members; and d. a control system in communication with the first electric motor and configured to receive a first torque value output indicating first applied torque, wherein first applied torque is the torque applied by the first electric motor to drive the one or more of the plurality of vehicle ground-engaging rotatable members, wherein the control system is configured to: i. based on the first torque value, determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly; ii. if a determination is made to apply or change a counterbalance pressure at the first working assembly, determine a counterbalance value based on the first torque value; and iii. apply a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.

2. The machine of claim 1, wherein the first electric motor is configured to drive a first axle operably connected to a first rotatable member and a second rotatable member of the plurality of vehicle ground-engaging rotatable members.

3. The machine of claim 2, further comprising a second electric motor configured to drive a second axle operably connected to a third rotatable member and a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members, wherein the control system is in communication with the second electric motor and is configured to receive a second torque value output indicating second applied torque, wherein second applied torque is the torque applied by the second electric motor to the third rotatable member and the fourth rotatable member.

4. The machine of claim 1, wherein the control system is configured to increase the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque is below a lower torque threshold.

5. The machine of claim 1, wherein the control system is configured to decrease the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque is above an upper torque threshold.

6. The machine of claim 4, wherein the control system is configured to: increase the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque is below a lower torque threshold and decrease the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque is above an upper torque threshold.

7. The machine of claim 1, wherein: the first electric motor is configured to drive a first rotatable member of the plurality of vehicle ground-engaging rotatable members;a second electric motor is configured to a second rotatable member of the plurality of vehicle ground-engaging rotatable members; a third electric motor is configured a third rotatable member of the plurality of vehicle ground-engaging rotatable members; and a fourth electric motor is configured to a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members; wherein the control system is configured to: receive the first torque value output indicating the first applied torque, wherein the first applied torque is torque applied by the first electric motor to the first rotatable member; receive a second torque value output indicating the second applied torque, wherein the second applied torque is torque applied by the second electric motor to the second rotatable member; receive a third torque value output indicating the third applied torque, wherein the third applied torque is torque applied by the third electric motor to the third rotatable member; and receive a fourth torque value output indicating the fourth applied torque, wherein the fourth applied torque is torque applied by the fourth electric motor to the fourth rotatable member.

8. The machine of claim 1, wherein the working assembly ground-engaging rotatable members remain in contact with a ground surface while the determined counterbalance pressure of the determined counterbalance value is applied to the first working assembly.

9. The machine of claim 1, wherein each connection assembly is configured to raise the one working assembly from a working position in which the working assembly ground-engaging rotatable members remain in contact with a ground surface to a raised position in which the working assembly ground-engaging rotatable members are raised above the ground surface.10 The machine of claim 1, wherein the working assembly ground-engaging rotatable members are configured to follow the ground surface independently of the vehicle ground-engaging rotatable members.

11. The machine of claim 1, wherein the control system is configured to: compare the first torque value to a maximum expected torque value; and increase the counterbalance pressure to the first working assembly if the first torque value is above the maximum torque expected value.

12. The machine of claim 11, further comprising a slope sensor configured to output a slope value indicating a slope of the ground-working machine with respect to a horizontal reference plane, wherein the control system is configured to adjust the maximum expected torque value based on the slope value.

13. The machine of claim 12, wherein the control system is configured to increase the maximum expected torque value as the slope value increases.

14. The machine of claim 11, wherein when the first torque value is above the maximum expected torque value, if the control system receives a second torque value indicating a rapid decrease in the torque applied by the first electric motor, the control system is configured to increase the counterbalance pressure to the first working assembly.

15. The machine of claim 14, wherein the control system is configured to: receive a signal from the vehicle that regenerative braking is activated; not increase the counterbalance pressure to the first working assembly upon detecting that regenerative braking is activated.

16. A method of operating a ground-working machine, the machine comprising a vehicle comprising a first electric motor and a plurality of vehicle ground-engaging rotatable members and a first working assembly comprising a plurality of working assembly ground-engaging rotatable members, wherein the first working assembly is operatively connected to the vehicle by a first connection assembly, wherein the first connection assembly is configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle groundengaging rotatable members, the method comprising:receiving a first torque value output indicating first applied torque, wherein first applied torque is torque applied by the first electric motor to drive the one or more of the plurality of vehicle ground-engaging rotatable members; based on the first torque value, determining whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly; if a determination is made to apply or change a counterbalance pressure at the first working assembly, determining a counterbalance value based on the first torque value; and applying a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.

17. The method of claim 16, further comprising: comparing the first torque value to a maximum expected torque value; and increasing the counterbalance pressure to the first working assembly if the first torque value is above the maximum torque expected value.

18. The method of claim 17, the vehicle further comprising a slope sensor configured to output a slope value indicating a slope of the ground-working machine with respect to a horizontal reference plane, the method further comprising adjusting the maximum expected torque value based on the slope value.

19. The method of claim 18, further comprising increasing the maximum expected torque value as the slope value increases.

20. The method of claim 17, further comprising: detecting that the first torque value is above the maximum expected torque value; receiving a second torque value indicating a rapid decrease in the torque applied by the first electric motor; and increasing the counterbalance pressure to the first working assembly21. A ground-working machine comprising :a. a vehicle comprising: i. a plurality of vehicle ground-engaging rotatable members configured to contact a ground surface; ii. a first electric motor to drive one or more of the plurality of vehicle ground-engaging rotatable members; b. a first working assembly comprising a ground-working unit and a plurality of working assembly ground-engaging rotatable members configured to contact the ground surface; c. a first connection assembly, wherein the first connection assembly attaches the first working assembly to the vehicle, the first connection assembly configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle ground-engaging rotatable members; and d. a control system in communication with the first electric motor and configured to receive a first torque value output indicating first applied torque, wherein first applied torque is the torque applied by the first electric motor to drive the one or more of the plurality of vehicle ground-engaging rotatable members, wherein the control system is configured to: i. based on the first torque value, determine whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly; ii. if a determination is made to apply or change a counterbalance pressure at the first working assembly, determine a counterbalance value based on the first torque value; and iii. apply a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.22 The machine of claim 21, wherein the first electric motor is configured to drive a first axle operably connected to a first rotatable member and a second rotatable member of the plurality of vehicle ground-engaging rotatable members.

23. The machine of claim 22, further comprising a second electric motor configured to drive a second axle operably connected to a third rotatable member and a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members, wherein the control system is in communication with the second electric motor and is configured to receive a second torque value output indicating second applied torque, wherein second applied torque is the torque applied by the second electric motor to the third rotatable member and the fourth rotatable member.

24. The machine of any of claims 21-23, wherein the control system is configured to increase the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque is below a lower torque threshold.

25. The machine of any of claims 21-24, wherein the control system is configured to decrease the counterbalance pressure applied to the first working assembly upon determining that the first torque value output indicates a first applied torque is above an upper torque threshold.

26. The machine of claim 25, wherein the control system is configured to: increase the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque is below a lower torque threshold and decrease the counterbalance pressure applied to the second working assembly upon determining that the second torque value output indicates a second applied torque is above an upper torque threshold.

27. The machine of any of claims 21-26, wherein: the first electric motor is configured to drive a first rotatable member of the plurality of vehicle ground-engaging rotatable members; a second electric motor is configured to a second rotatable member of the plurality of vehicle ground-engaging rotatable members; a third electric motor is configured a third rotatable member of the plurality of vehicle ground-engaging rotatable members; anda fourth electric motor is configured to a fourth rotatable member of the plurality of vehicle ground-engaging rotatable members; wherein the control system is configured to: receive the first torque value output indicating the first applied torque, wherein the first applied torque is torque applied by the first electric motor to the first rotatable member; receive a second torque value output indicating the second applied torque, wherein the second applied torque is torque applied by the second electric motor to the second rotatable member; receive a third torque value output indicating the third applied torque, wherein the third applied torque is torque applied by the third electric motor to the third rotatable member; and receive a fourth torque value output indicating the fourth applied torque, wherein the fourth applied torque is torque applied by the fourth electric motor to the fourth rotatable member.

28. The machine of any of claims 21-27, wherein the working assembly groundengaging rotatable members remain in contact with a ground surface while the determined counterbalance pressure of the determined counterbalance value is applied to the first working assembly.

29. The machine of any of claims 21-28, wherein each connection assembly is configured to raise the one working assembly from a working position in which the working assembly ground-engaging rotatable members remain in contact with a ground surface to a raised position in which the working assembly ground-engaging rotatable members are raised above the ground surface.

30. The machine of any of claims 21-29, wherein the working assembly groundengaging rotatable members are configured to follow the ground surface independently of the vehicle ground-engaging rotatable members.

31. The machine of any of claims 21-30, wherein the control system is configured to: compare the first torque value to a maximum expected torque value; andincrease the counterbalance pressure to the first working assembly if the first torque value is above the maximum torque expected value.

32. The machine of claim 31, further comprising a slope sensor configured to output a slope value indicating a slope of the ground-working machine with respect to a horizontal reference plane, wherein the control system is configured to adjust the maximum expected torque value based on the slope value.33 The machine of claim 32, wherein the control system is configured to increase the maximum expected torque value as the slope value increases.

34. The machine of any of claims 31-32, wherein when the first torque value is above the maximum expected torque value, if the control system receives a second torque value indicating a rapid decrease in the torque applied by the first electric motor, the control system is configured to increase the counterbalance pressure to the first working assembly.

35. The machine of claim 34, wherein the control system is configured to: receive a signal from the vehicle that regenerative braking is activated; not increase the counterbalance pressure to the first working assembly upon detecting that regenerative braking is activated.

36. A method of operating a ground-working machine, the machine comprising a vehicle comprising a first electric motor and a plurality of vehicle ground-engaging rotatable members and a first working assembly comprising a plurality of working assembly ground-engaging rotatable members, wherein the first working assembly is operatively connected to the vehicle by a first connection assembly, wherein the first connection assembly is configured to apply a counterbalance pressure to the first working assembly, wherein the counterbalance pressure shifts weight from the working assembly ground-engaging rotatable members to the vehicle groundengaging rotatable members, the method comprising:receiving a first torque value output indicating first applied torque, wherein first applied torque is torque applied by the first electric motor to drive the one or more of the plurality of vehicle ground-engaging rotatable members; based on the first torque value, determining whether to apply a counterbalance pressure or change an already-applied counterbalance pressure to the first working assembly via the first connection assembly; if a determination is made to apply or change a counterbalance pressure at the first working assembly, determining a counterbalance value based on the first torque value; and applying a counterbalance pressure of the determined counterbalance value via the first connection assembly to the first working assembly for which a determination was made to apply or change a counterbalance pressure.

37. The method of claim 36, further comprising: comparing the first torque value to a maximum expected torque value; and increasing the counterbalance pressure to the first working assembly if the first torque value is above the maximum torque expected value.

38. The method of claim 37, the vehicle further comprising a slope sensor configured to output a slope value indicating a slope of the ground-working machine with respect to a horizontal reference plane, the method further comprising adjusting the maximum expected torque value based on the slope value.

39. The method of claim 38, further comprising increasing the maximum expected torque value as the slope value increases.

40. The method of any of claims 37-39, further comprising: detecting that the first torque value is above the maximum expected torque value; receiving a second torque value indicating a rapid decrease in the torque applied by the first electric motor; and increasing the counterbalance pressure to the first working assembly

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