Control of the gearbox with activated power take-off

Abstract

Powertrain, which includes: a transmission with a power take-off and an output shaft that delivers torque to the vehicle wheels, the power take-off being coupled to the output shaft via a planetary gear set; and Control unit containing executable commands that cause the control unit to operate the drivetrain in a first speed control mode, in which an output shaft speed is controlled via the control unit in response to a vehicle containing the drivetrain driving with rotating wheels and simultaneously delivering power to the power take-off.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 518,316, entitled "CONTROL OF TRANSMISSION WITH ACTIVATED POWER TAKE-OFF," filed August 8, 2023. The entire contents of the above-referenced application are hereby incorporated by reference for all purposes. TECHNICAL FIELD

[0002] The present disclosure relates to a transmission with power take-off ports for driving loads that can be directly coupled to a vehicle driveline via gears. Loads may also include those that are driven while the vehicle is in motion. BACKGROUND AND SUMMARY

[0003] A vehicle may include a transmission with an output shaft connected to the vehicle wheels and a power take-off connected to a transmission output shaft through a planetary gear set. The power take-off may transfer torque from an internal combustion engine or other power source (e.g., an electric machine, a fuel cell, etc.) to a device connected to a transmission but not contributing to vehicle movement. For example, the power take-off may provide mechanical power to a pump that supplies pressurized fluid to a pump in a hydraulic circuit. The power take-off may rotate at the desired speed when the vehicle is stationary and not traveling on a road with rotating wheels. The requested speed may be dictated by the device connected to the power take-off.However, if the vehicle is traveling on a road with rotating wheels, the power take-off may be disabled (e.g., set to zero speed) because it may be difficult to maintain the desired wheel torque when the power take-off load changes. For example, because the torque at the transmission output shaft and the torque at the power take-off output are coupled, it may be possible to deliver torque to the transmission output shaft or power take-off in an undesired direction of rotation and / or with an undesired speed change. Furthermore, driving with the wheels rotating and the power take-off engaged may require the human driver to learn unnatural driving behaviors to steer the vehicle in the intended manner.While it may be possible to dynamically estimate the torque delivered to the vehicle's power take-off and wheels, or to estimate the torque at a transmission input shaft and a power take-off coupled to the transmission input shaft, producing these estimates may be financially prohibitive. Furthermore, system complexity may be greater, and there is a higher likelihood of sensor compromise. Therefore, it may be desirable to provide a way to control a power take-off output and a transmission shaft output in a way that reduces the risk of unintended rotation direction, without having to accurately estimate the torque at the transmission output shaft and power take-off.

[0004] The inventors have recognized the above problems and developed a powertrain comprising: a transmission having a power take-off and an output shaft that delivers torque to vehicle wheels, the power take-off being coupled to the output shaft via a planetary gear set; and a control unit containing executable instructions that cause the control unit to operate the powertrain in a first speed control mode in which an output shaft speed is controlled via the control unit in response to a vehicle including the powertrain traveling with rotating wheels while delivering power to the power take-off.

[0005] By operating the driveline in a speed control mode, in which vehicle speed is controlled while driving and a vehicle power take-off is engaged, it may be possible to prevent unintended vehicle movement and operate the power take-off. Furthermore, additional financial expenditures for estimating torque at various points along the driveline can be avoided. Because a speed controller uses vehicle speed feedback rather than an estimated torque at a specific point along the driveline, the vehicle can be controlled with a readily available speed feedback signal, eliminating the need to estimate torque at the transmission output shaft and power take-off.

[0006] The present description can offer several advantages. In particular, the approach can increase powertrain functionality by enabling a vehicle with a second power take-off to operate in the desired manner when the vehicle is in motion. Furthermore, the method can reduce the risk of a vehicle traveling in an unintended direction and unintentionally changing the vehicle's speed. Furthermore, the concept can enable the driver to operate the vehicle in a natural or expected manner.

[0007] It should be understood that the above summary is intended to introduce, in simplified form, a selection of concepts that are further explained in the detailed description. It is not intended to identify essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages noted above or elsewhere in this disclosure.

[0008] The accompanying drawings are incorporated herein by reference. The drawings described herein illustrate embodiments of the subject matter disclosed herein and illustrate selected principles and teachings of the present disclosure. However, the drawings do not illustrate all possible implementations of the subject matter disclosed herein and are not intended to limit the scope of the present disclosure in any way. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 is a schematic diagram of an exemplary vehicle powertrain including a transmission; Fig. 2 is a block diagram of an exemplary transmission; Fig. 3 shows a detailed schematic representation of a transmission; Fig. Figure 4 shows a block diagram for operating a vehicle and a transmission in speed control mode; Fig. Figure 5 shows a permissible torque range when operating a vehicle in speed control mode while a second power take-off is activated; and Fig. Figure 6 shows an example of a proportional-integral-derivative controller for operating a vehicle in a speed control mode. DETAILED DESCRIPTION

[0009] The following description relates to systems and methods for operating a moving vehicle that includes a power take-off device for driving external loads. The vehicle may have a transmission with two power take-off ports that can be driven by an external power source or by an electric machine included in the transmission. The transmission may be included in a two- or four-wheel drive vehicle, as described in Fig. 1. The gearbox can be mounted as shown in Fig. 2 and the transmission may contain components that are Fig. 3. The gearbox can be operated according to the control block diagram shown in the block diagram of Fig. 4. The transmission control can limit the wheel torque between two threshold values, as shown in Fig. 5. In one example, the control unit may be a proportional-integral-derivative (PID) controller, as shown in Fig. 6 shown.

[0010] Fig. 1 shows an example vehicle powertrain 199 included in vehicle 10. Vehicle 10 includes a front end 110 and a rear end 111. Vehicle 10 includes front wheels 102 and rear wheels 103. Vehicle 10 includes a power source 12 (e.g., an internal combustion engine or an electric machine) that can selectively provide motive power to front axle 191 and rear axle 190. In other examples, power source 12 can provide motive power to only front axle 191 or only rear axle 190. As shown, power source 12 is mechanically coupled to transmission 14 via transmission input shaft 129. In some examples, the engine crankshaft (not shown) can be coupled to transmission input shaft 129. The transfer case 193 transfers the mechanical power from the transmission output shaft 130 to the front axle 191 and rear axle 190.

[0011] The electrical energy storage device 16 (e.g., a traction battery or capacitor) may supply power to the electric machines in the transmission 14. The transmission 14 may supply mechanical energy to the mechanically driven accessories 18 and 20. The transmission 14 may be operated via the controller 15. In this example, the controller 15 is configured to control electric machines (not shown), clutches (not shown), and brakes (not shown) in the transmission 14. The controller 15 may switch the operating modes of the transmission 14 by setting the states of the clutches and brakes, as shown in Fig. 4. The controller 15 may also receive a position of a driver demand pedal 100 from the driver demand pedal position sensor 108, which may be an input signal for determining the operating state of the transmission 14. The driver demand pedal 100 and the driver demand pedal position sensor 108 may respond to movement caused by the human driver 109. The brake pedal 122 may be applied by the human driver 109, and the brake pedal sensor 120 provides an indication of the brake pedal position to the controller 15. The controller 15 may receive data from the sensors 177. The sensors 177 may include, but are not limited to, a vehicle speed sensor, a transmission temperature sensor, a transmission input shaft speed sensor, a transmission output shaft speed sensor, wheel speed sensors, and an ambient temperature sensor.The controller 15 can adjust operating states of the vehicle powertrain 199 by adjusting operating states of the actuators 178. The actuators 178 can include, among others, electric machines, inverters, clutches (CO-C2), brakes (B1 / B2), and engine torque actuators (throttle, cam, injectors, spark plug actuator). The controller 15 includes a processor 15a for executing instructions, a read-only memory 15b, and a random access memory 15c. In this example, a single controller 15 is shown, but in other examples, multiple controllers can cooperate in a distributed system to perform the methods described herein. The controller 15 can receive inputs from the human-machine interface 195 (e.g., touchscreen display, push buttons, etc.) and provide outputs to that interface.

[0012] In Fig. 2 shows a block diagram of the transmission 14. The transmission 14 is shown with five ports, labeled P1-P5. Port 1 (P1) is configured to receive mechanical energy from a power source 12 (e.g., an internal combustion engine or the electric machine). Alternatively, port 1 may supply mechanical energy to the external energy source 12. Port 2 (P2) is a port that receives electrical energy from the electrical energy storage device 16. Alternatively, port 2 may supply the electrical energy for the electrical energy storage device 1. The electrical ports 2 are directly electrically connected to a first inverter 206 and a second inverter 204. The first inverter 206 may convert direct current (DC) to alternating current (AC). The alternating current may be supplied from the first inverter 206 to the first electric machine 210.Likewise, the alternating current from the second inverter 204 can be supplied to the second electric machine 208. Alternatively, the first and second electric machines 210 and 208 can supply alternating current to the inverters 206 and 204. The electric machines 210 and 208 can supply mechanical power to gears, clutches, and brakes 202. Therefore, the electric machines 210 and 208 can also be referred to as drive sources. The gears, clutches, and brakes 202 can transmit mechanical power to the output ports P3-P5. The output port P3 can transmit mechanical power to the wheels 103. The output port P4 can transmit mechanical power to the power take-off (PTO 1) 212 and the accessories 18, where the accessories 18 do not include vehicle wheels.The output port P5 can transmit mechanical power to the power take-off (PTO 2) 214 and the accessories 20, wherein the accessories 20 do not include vehicle wheels.

[0013] In Fig. 3 shows a detailed view of an example of a transmission 14. In this example, the power source 12 is coupled to the transmission input shaft 129. The transmission input shaft 129 is coupled to clutch C0, and clutch C0 can selectively couple the transmission input shaft 129 to the interconnecting shaft 304. Clutch C0 is directly connected to the ring gear 326 of the first planetary gear set PT1 and the gear 360 of the power take-off PTO 1 via the interconnecting shaft 304. The gear 360 of the power take-off 1 can be coupled to accessories 18 via the power take-off 1 shaft 362. The first planetary gear set PT1 also includes planet gears 316 and a sun gear 322. The sun gear 322 is coupled to the gear 340 of the power take-off 2 and the electric machine 210. The planet gears 316 couple the sun gear 322 to the ring gear 326. The carrier 328 carries the planet gears 316.The gear 340 of the power take-off 2 can be selectively coupled to the output shaft 342 of the power take-off 2 via the clutch C2 of the power take-off 2. The output shaft 342 of the power take-off 2 can be directly coupled to accessories 20, and the accessories 20 are not connected to the vehicle wheels.

[0014] The connecting shaft 304 can be selectively connected to the electric machine 208 and the sun gear member 306 of the third planetary gear set PT3 by closing the input-coupled clutch C1. The sun gear member 306 of the third planetary gear set PT3 is coupled to the planet gears 308. The planet gears 308 are coupled to the ring gear member 310, and the planet gears 308 are supported by the carrier member 312. The planet gears 308 are coupled to the ring gear member 318 of the second planetary gear set PT2 and the planet gears 316 of the first planetary gear set PT1 via the carrier member 312 of the third planetary gear set PT3 and the carrier member 328 of the first planetary gear set PT1. The carrier member 328 of the first planetary gear set PT1 is coupled to the gears 103 via the transmission output shaft 130. The brake B1 can be closed to anchor the ring gear 310 of the third planetary gear set PT3 or to connect it to the transmission housing 399.

[0015] The second planetary gear set PT2 includes a sun gear 314 coupled to the ring gear 310 of the first planetary gear set PT1. The planetary gears 308 of the second planetary gear set PT2 are coupled to the sun gear 314 of the planetary gear set PT2 and the ring gear 318 of the second planetary gear set PT2. The brake B2 can be closed to anchor the carrier 320 of the second planetary gear set PT2 or to connect it to the transmission housing 399.

[0016] Power take-off 1 is directly connected to connecting shaft 304. Therefore, when connecting shaft 304 rotates, output shaft 362 of power take-off 1 also rotates. Output shaft 362 of power take-off 1 can be rotated by closing clutch C0 when power source 12 rotates. Power take-off 1 can also be rotated via electric machine 208 by closing clutch C1. Power take-off 1 can rotate in any of the modes shown in the table. Fig. 4 are listed.

[0017] The power take-off 2 can rotate and supply the accessories 20 with mechanical energy in three modes, as shown in Fig. 4. In a rollback brake mode, brakes B1 and B2 can be closed to block rotation of transmission output shaft 130, and output shaft 342 of power take-off 2 can be rotated by the torque generated by electric machine 210 and / or drive source 12. In this way, output shaft 342 of power take-off 2 can rotate at a speed that is a multiple of the speed of drive source 12 and connecting shaft 304.

[0018] The output shaft 342 of the power take-off 2 can be rotated when the clutch C1 is open, C2 is closed, and C0 is open or closed. The output shaft 342 of the power take-off 2 can also transmit mechanical torque to the accessories 20 when the brake B1 is open, B2 is closed, C1 is open, C2 is closed, and C0 is open or closed. The application of the brake B2 prevents the rotation of the carrier 320, allowing the gear 340 of the power take-off 2 to rotate when the power source 12 or the electric machine 208 drives the transmission output shaft 130 via the connecting shaft 304, the second planetary gear set PT2, and the first planetary gear set PT1.Power can flow from the drive source 12 via the clutch C0 to the connecting shaft 304. The connecting shaft 304 can transmit torque to the ring gear 326, causing the planetary gears 316 to rotate along with the sun gear 322, allowing the carrier 328 and the transmission output shaft 130 to rotate. The rotation of the sun gear 322 enables the rotation of the gear 340 of the power take-off 2. The output shaft 342 of the power take-off 2 can rotate when the clutch C2 is closed.

[0019] The output shaft 342 of the power take-off 2 can also be rotated when the clutch C1 is open, C2 is closed, and C0 is open or closed. The output shaft 342 of the power take-off 2 can also transmit mechanical torque to the accessories 20 when the brake B1 is closed, B2 is open, C1 is open, C2 is closed, and C0 is open or closed. Applying the brake B1 prevents the ring gear 310 and the sun gear 306 from rotating. Energy can flow from the drive source 12 via the clutch C0 to the connecting shaft 304. The connecting shaft 304 can transmit torque to the ring gear 326, causing the planetary gears 316 to rotate together with the sun gear 322, allowing the carrier 328 and the transmission output shaft 130 to rotate. The rotation of the sun gear 322 enables the rotation of the gear 340 of the power take-off 2. The output shaft 342 of the power take-off 2 can rotate when the clutch C2 is closed.

[0020] Thus, the system can Fig. 1-3 provide a powertrain comprising: a transmission having a power take-off and an output shaft that delivers torque to vehicle wheels, the power take-off coupled to the output shaft via a planetary gear set; and a controller having executable instructions that cause the controller to operate the powertrain in a first speed control mode in which a speed of the output shaft is controllably controlled via the controller in response to a vehicle including the powertrain traveling with rotating wheels while simultaneously delivering power to the power take-off. In a first example, the powertrain further comprises operating the power take-off in a second speed control mode while the powertrain is operating in the first speed control mode.In a second example, which may include the first example, the powertrain includes a first speed control unit of the control unit controlling the speed of the output shaft, and a second speed control unit of the control unit controlling the power take-off. In a third example, which may include one or more of the first and second examples, the powertrain includes the first speed control unit regulating the output shaft to a first speed, the second speed control unit regulating the speed of the power take-off to a second speed, and the second speed being different from the first speed.In a fourth example, which may include one or more of the first through third examples, the powertrain includes the first speed control unit adjusting torque of a power source in response to a difference between a requested vehicle speed and an actual vehicle speed. In a fifth example, which may include one or more of the first through fourth examples, the powertrain includes the requested vehicle speed based on a position of a driver request pedal. In a sixth example, which may include one or more of the first through fifth examples, the powertrain includes the second speed control unit adjusting torque of an electric machine in response to a difference between a requested power take-off speed and an actual power take-off speed.

[0021] Thus, the system Fig. 1-3 also provides a powertrain comprising: a transmission including a first power take-off port including a power take-off shaft rotating at a multiple of a speed of a first shaft, the first shaft coupled to a ring gear of a first planetary gear set, a second shaft configured to deliver power to vehicle wheels, the second shaft coupled to carrier planet gears of the first planetary gear set; and a second power take-off port, the second power take-off port coupled to a sun gear of the first planetary gear set, the first power take-off port and the second power take-off port not configured to be coupled to the second shaft except via the first planetary gear set; and a controller including executable instructions that cause the controller tooperate the powertrain in a speed control mode in response to a vehicle including the powertrain traveling with rotating wheels while simultaneously delivering power to the second power take-off port. In a first example, the powertrain includes the speed control mode including controlling a vehicle speed, and further comprising: additional instructions for controlling the vehicle speed via vehicle speed feedback. In a second example, which may include the first example, the powertrain further includes additional instructions for controlling the vehicle speed in response to a requested vehicle speed, wherein the requested vehicle speed is based on a position of a driver request pedal. In a third example, which may include one or both of the first and second examples,The powertrain further includes additional instructions for regulating the speed of a shaft of the second power take-off port. In a fourth example, which may include one or more of the first through third examples, the powertrain further includes additional instructions for limiting the wheel torque output to a value between a first wheel torque threshold and a second wheel torque threshold.

[0022] In Fig. 4 is an exemplary block diagram 400 of a vehicle speed controller 402 and a power take-off speed controller 403 for a second power take-off (P5 of Fig. 1) for the drivetrain 199 from Fig. 1. The vehicle speed controller 402 and the power take-off speed controller 403 can be selected in the controller 15 from Fig. 1 as executable instructions stored in a non-transitory memory. Furthermore, the block diagram 400 may be used in conjunction with the system of Fig. 1-3 actions that are performed in the physical world to determine an operating state of the system from Fig. 1-3 about setting the positions of the different actuators.

[0023] The vehicle speed controller 402 may receive inputs via a driver demand pedal 100 and a brake pedal. The driver demand pedal position and the brake pedal position are input to block 418. Block 418 converts the brake pedal position and the driver demand pedal position into a desired vehicle speed. In one example, block 418 may include a function or table 419 referenced or indexed by the driver demand pedal position and the brake pedal position. The function or table outputs an empirically determined requested vehicle speed. Requested vehicle speed values ​​may be determined by applying the driver demand pedal and the brake pedal, with the requested vehicle speed being adjusted until the vehicle performance targets are met. The requested vehicle speed is input to block 416.

[0024] Block 416 represents a vehicle speed controller. In one example, the vehicle speed controller is a proportional-integral-derivative (PID) controller, as shown in Fig. 6. Alternatively, the vehicle speed controller may be a linear-quadratic controller or another known controller type. Block 416 outputs a requested wheel torque to block 414. The controller of block 416 may receive feedback about the vehicle speed and adjust the requested wheel torque according to a vehicle speed error, which is a difference between the requested vehicle speed and the actual vehicle speed. The controller of block 416 may adjust the actual vehicle speed to follow a requested vehicle speed, which is a function of wheel speed, by adjusting the wheel torque to allow the wheel torque to vary so that the actual vehicle speed matches the desired vehicle speed.In this way, the drive train 119 is operated in a speed control mode.

[0025] In block 414, the requested wheel torque may be limited by a filter to be within an upper and a lower torque threshold, as shown in Fig. 5. The output of block 414 is a filtered requested wheel torque, and the powertrain 119 may be commanded to the filtered requested wheel torque. The powertrain 119 may respond to the filtered requested wheel torque by generating wheel torque via a power source of the powertrain 119. The wheel speed, which may indicate vehicle speed, is returned to block 416, where it is used to correct the requested wheel torque.

[0026] Blocks 420 and 422 are optional, as indicated by the dashed lines. If block 420 is present, it receives input from the driver demand pedal position and the brake pedal position. A table or function 421 can be referenced or indexed by the driver demand pedal position and the brake pedal position. Table or function 421 outputs a demanded wheel torque, and the demanded wheel torque is input to block 422.

[0027] If block 422 is present, the powertrain 119 may operate in torque control mode or in vehicle speed control mode. If the human driver 109 requests operation of PTO 2 and the vehicle is traveling with the wheels turning, block 422 may switch to request the filtered wheel torque from block 414 from the powertrain 119. Conversely, if the human driver 109 does not request operation of PTO 2, block 422 may switch to request the wheel torque requested by block 420 from the powertrain 119. If block 422 is not present, the filtered requested vehicle speed is requested directly from the powertrain 119. Furthermore, if block 422 is not present, the vehicle may also operate only in vehicle speed control mode. The powertrain 119 may control the torque output of one or more power sources (e.g.,an electric machine or an internal combustion engine) to produce the torque that produces the desired vehicle speed, wheel torque and power take-off speed.

[0028] In addition to the vehicle speed controller 402, a power take-off 2 speed controller 403 is included to control the speed of the power take-off 2. The human operator 109 may request a speed for the power take-off 2 via the human-machine interface 404. The human-machine interface may output a requested speed for the power take-off 2 to block 406.

[0029] Block 406 represents a power take-off speed controller for power take-off 2. In one example, the vehicle speed controller is a proportional-integral-derivative (PID) controller, similar to the speed controller described with reference to Fig. 6. Alternatively, the PTO speed controller may be a linear-quadratic controller or another known controller type. Block 406 outputs a requested PTO speed (e.g., a PTO speed requested by a human operator or a control unit) to block 408. The control unit of block 406 may receive speed feedback from PTO 2 and adjust the requested PTO 2 torque according to a PTO 2 speed error, which is a difference between the requested PTO 2 speed and the actual PTO 2 speed.The controller of block 506 may adjust the actual speed of PTO 2 to follow a requested speed of PTO 2 by adjusting a torque command for PTO 2 to allow the torque of PTO 2 to vary so that the actual speed of PTO 2 matches the requested speed of PTO 2. In this way, the powertrain 119 may operate PTO 2 in a speed control mode.

[0030] At block 408, the requested speed of PTO 2 may be limited using a filter to be within an upper and lower torque threshold. The output of block 408 is a filtered requested speed of PTO 2, and powertrain 119 may be commanded to the filtered requested speed of PTO 2. Powertrain 119 may respond to the filtered requested speed of PTO 2 by generating PTO 2 via a power source of powertrain 119. The speed of PTO 2 is fed back to block 406, where it is used to correct the requested speed of PTO 2. The filtered requested speed of PTO 2 is commanded to powertrain 119. Powertrain 119 may rotate accessory 20 (e.g., a pump) at the requested speed of PTO 2.

[0031] Thus, the control block diagram from Fig. 4 proposes a method of operating a powertrain, comprising operating the powertrain in a speed control mode in which a speed of a vehicle speed is controlled to a commanded vehicle speed via a controller and in response to a power take-off supplying power to a device external to a transmission and a vehicle including the transmission and traveling with rotating wheels. In a first example, the method of operating the powertrain includes the speed control mode including adjusting the speed of the vehicle to the commanded vehicle speed while varying the torque supplied via the powertrain.In a second example, which may include the first example, the method of operating the powertrain further comprises supplying torque across the powertrain as a function of a difference between the requested vehicle speed and the vehicle speed. In a third method, which may include one or more of the first and second methods, the method of operating the powertrain further comprises the controller being a proportional-integral-derivative controller. In a fourth method, which may include one or more of the first through third methods, the method of operating the powertrain further comprises operating the power take-off in a speed control mode via a second controller.In a fifth method, which may include one or more of the first through fourth methods, the method of operating the powertrain includes where the second controller is a proportional-integral-derivative controller. In a sixth method, which may include one or more of the first through fifth methods, the method of operating the powertrain includes where operating the powertrain in speed control mode comprises adjusting a wheel torque output of the powertrain, and further comprises: limiting the wheel torque output to a value between a first threshold torque and a second threshold torque. In a seventh method, which may include one or more of the first through sixth methods, the method of operating the powertrain includes where the first threshold torque and the second threshold torque vary with vehicle speed.

[0032] In another representation, the procedure looks like Fig. 4 proposes a method of operating a powertrain, comprising: operating the powertrain in a speed control mode in which a speed of a vehicle speed is controlled to a commanded vehicle speed via a control unit and in response to a power take-off supplying power to a device external to a transmission and to a vehicle including the transmission and traveling with rotating wheels; and not operating the powertrain in the speed control mode and operating the powertrain in a torque control mode in response to the power take-off supplying no power to the device external to the transmission and to the vehicle including the transmission and traveling with rotating wheels. In the torque control mode, the torque of the vehicle (e.g.The vehicle speed (e.g., wheel torque) is adjusted to match a target or requested torque, while the vehicle speed is allowed to vary. In speed control mode, the vehicle speed is adjusted to follow a target speed or requested vehicle speed, and the vehicle torque (e.g., wheel torque) is allowed to vary.

[0033] In Fig. Figure 5 is a graph showing the permissible torque range for a driveline operating with PTO 2 active (i.e., rotating and supplying torque to an external accessory rather than the vehicle's wheels) when the vehicle is traveling with the wheels rolling. The horizontal axis represents vehicle speed, and vehicle speed increases to the right of the vertical axis. The magnitude of vehicle speed increases to the left of the vertical axis. The vertical axis represents wheel torque, and wheel torque is positive and increases in the direction of the vertical axis arrow above the horizontal axis. The wheel is negative below the horizontal line, and the negative wheel magnitude increases in the direction of the vertical axis arrow, which is below the horizontal line.

[0034] The solid line 502 represents an upper torque threshold that the wheel torque must not exceed when the driveline is operating with PTO 2 active and the vehicle is traveling with the wheels spinning. The dashed line 504 represents a negative torque threshold that the wheel torque must not exceed when the driveline is operating with PTO 2 active and the vehicle is traveling with the wheels spinning. Thus, the allowable range for the wheel torque is between threshold 502 and threshold 504. The commanded or final wheel torque may vary between the thresholds (502 and 504), but its magnitude must not be in the range above threshold 502 or below threshold 504.

[0035] The vehicle speeds between vertical line 550 and vertical line 551 represent a range in which the wheel torque increases with decreasing negative vehicle speed (e.g., when reversing). The vehicle speeds between vertical line 552 and vertical line 553 represent a range in which the wheel torque decreases with increasing positive vehicle speed (e.g., when traveling forward).

[0036] It can be observed that at lower vehicle speeds, greater wheel torque can be generated via the driveline in both the forward (positive) and reverse (negative) directions. This allows for a low requested vehicle speed (e.g., zero) via the vehicle brake setting while PTO 2 is active. At higher vehicle speeds, the regenerative braking torque is limited to a small value, allowing the vehicle to coast to a stop if the actual vehicle speed is greater than the requested vehicle speed (e.g., without transferring drive torque to the wheels).

[0037] In Fig. 6 shows a block diagram of an exemplary proportional-integral-derivative (PID) controller 14. The PID controller of Fig.6 can be used as a vehicle speed controller and / or power take-off speed controller by simply adjusting the signals input to the PID controller and passing the PID controller output to a suitable system or actuator.

[0038] At summing point 606, the actual or measured vehicle speed is subtracted from the requested vehicle speed to determine a vehicle speed error. The vehicle speed error is provided to blocks 608-612. In block 608, a proportional scalar or gain variable (e.g., a real number) K p multiplied by the vehicle speed error (e), which is a function of time, to produce a proportional component of the PID controller output. Block 608 outputs the proportional component of the PID controller to summing junction 614. At block 610, an integral scalar or gain variable Ki (e.g., a real number) is multiplied by the integral of the vehicle speed error (e) to generate an integral component of the PID controller output. Block 610 outputs the integral component of the PID controller to summing junction 614. In block 612, a derived scalar or gain variable (e.g., a real number) K d multiplied by the derivative of the vehicle speed error (e) to produce a derivative component of the PID controller output. Block 612 outputs the derivative component of the PID controller to summing junction 614. The PID controller adjustment of the generator torque is output from summing junction 614 to the powertrain 119 (not shown).

[0039] It should be noted that the example control and estimation routines included herein can be used with various powertrain and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and executed by the control system, including the controller, in combination with the various sensors, drive elements, and other engine hardware. Furthermore, portions of the methods can be physical actions performed in the real world to change the state of a device. The specific routines described herein can represent one or more arbitrary processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like.Thus, the various actions, operations, and / or functions illustrated can be performed in the order shown, in parallel, or in some cases, even without them. Accordingly, the order of processing is not required to achieve the features and benefits of the examples described here, but serves only to better illustrate and describe the process. One or more of the actions, operations, and / or functions illustrated may be performed repeatedly depending on the strategy used.Furthermore, the described actions, operations, and / or functions may graphically represent code to be programmed into a non-transitory memory of the computer-readable storage medium in the engine control system, wherein the described actions are performed by executing the instructions in a system including the various hardware components of the engine in combination with the electronic control system. One or more of the method steps described herein may also be omitted if desired.

[0040] It is understood that the configurations and routines disclosed herein are exemplary in nature and that these specific examples are not to be considered limiting, as numerous variations are possible. For example, the technology described above may be applied to powertrains incorporating various types of power sources, including various types of electric machines and / or transmissions. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or characteristics disclosed herein.

[0041] The following claims particularly point out certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims are to be construed as including the inclusion of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope than the original claims, are also to be considered included within the subject matter of the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 518,316

[0001]

Claims

[1] Powertrain that includes: a transmission having a power take-off and an output shaft that delivers torque to the vehicle wheels, the power take-off being coupled to the output shaft via a planetary gear set; and A control unit including executable instructions that cause the control unit to operate the powertrain in a first speed control mode in which an output shaft speed is controlled via the control unit in response to a vehicle including the powertrain traveling with rotating wheels while simultaneously delivering power to the power take-off. [2] The powertrain of claim 1, further comprising operating the power take-off in a second speed control mode while the powertrain is operating in the first speed control mode. [3] The powertrain of claim 2, wherein a first speed control unit of the control unit controls the output shaft speed and a second speed control unit of the control unit controls a power take-off speed. [4] The powertrain of claim 3, wherein the first speed control unit controls the output shaft speed to a first speed, wherein the second speed control unit controls the power take-off speed to a second speed, and wherein the second speed is different from the first speed. [5] The powertrain of claim 4, wherein the first speed control unit adjusts the torque of a power source in response to a difference between a requested vehicle speed and an actual vehicle speed. [6] The powertrain of claim 5, wherein the requested vehicle speed is based on the position of a driver request pedal. [7] A powertrain according to any preceding claim, wherein a second speed control unit adjusts the torque of an electric machine in response to a difference between a requested power take-off speed and an actual power take-off speed.

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