Control system with drivetrain locking

Abstract

Powertrain control system (26) for a mobile machine (10) comprising the following: a motor (22); a continuously variable transmission (24) which is operationally coupled to the motor (22); an operator input device (18b) configured to generate a signal indicating a desired speed of the motor (22); a feature selection device (18c) which can be used by an operator to select an actuation of a powertrain control feature; a control device (36) that communicates with the motor (22), the continuously variable transmission (24), the operator input device (18b) and the feature selection device (18c), wherein the control device (36) is configured to: Performing a determination that the operator has selected an actuation of the powertrain control feature via the feature selection device (18c); Locking a speed of the motor (22) based on the determination and the signal; Locking a torque output of the continuously variable transmission (24) based on the determination and locked speed of the motor (22); and Locking the torque output of the continuously variable transmission (24) at a percentage of a maximum available torque for a given travel speed of an associated mobile machine (10); wherein the percentage at which the torque output of the continuously variable transmission (24) is locked is based on the locked speed of the motor (22); and wherein the powertrain control system further includes a vehicle speed sensor (42) which is configured to generate a signal, which displays a travel speed of the mobile machine (10), wherein the control device (36) is connected to the travel speed sensor (42), wherein the control device (36) is further configured to: Determine, based on the signal from the travel speed sensor (42), that a current travel speed of the mobile machine (10) is associated with high-speed movement, while machine functions not related to movement are not used; and respond to this, reduce the speed of the engine (22) below the locked speed to a more fuel-efficient speed.

Description

Technical field

[0001] The present disclosure relates to a control system and in particular to a powertrain control system with an interlock that controls a transmission output torque and an engine speed. background

[0002] Machines such as wheel loaders, bulldozers, all-terrain trucks, and other heavy equipment are used to perform many tasks. To perform these tasks effectively, the machines require an engine that delivers significant torque through a transmission to one or more ground-engaging devices. To control the speed and torque output of these ground-engaging devices, the operator of these machines is typically provided with three different foot pedals. One of the three pedals is used to affect the engine's fuel supply. Another is used to affect the vehicle's braking. The third pedal is used to disengage the engine from the transmission and, when depressed far enough, also affects the vehicle's braking.

[0003] Although this configuration may be suitable when a mechanical stepped transmission is used to transfer power from the engine to the ground-engaging equipment, it may be insufficient and / or cumbersome when a continuously variable transmission (CVT) is used. A continuously variable transmission is a type of automatic transmission that provides an infinite number of output ratios within its gear ratio range. For example, a hydraulic continuously variable transmission may include a pump and a fluid motor that receives pressurized fluid from the pump. Depending on the pump's output flow rate and pressure, the motor speed and output torque at the ground-engaging equipment can be varied.When a continuously variable transmission (CVT) is used, a primary goal is to keep the engine running as stably and efficiently as possible. In this situation, the strategy described above—constantly varying the engine's fuel supply and / or constantly disconnecting the engine from the transmission—can work against this efficiency goal. Therefore, an alternative strategy is needed to control the operation of a machine using a CVT.

[0004] An alternative method of powertrain control is described in US Patent 7,854,681 B2 by Sopko et al., issued on December 21, 2010 (the '681 patent). The '681 patent describes a machine with a continuously variable transmission, left and right operator pedals, a gear selector, and a control device that communicates with the continuously variable transmission, the pedals, and the gear selector. The left foot pedal generates a first signal indicating a desired amount of power to be transmitted to drive the machine. The right foot pedal generates a second signal indicating a desired engine speed. The gear selector generates a third signal associated with a travel speed limit for the machine. The control device generates a torque output command for the continuously variable transmission, which is a function of the first and second signals.The torque output command is then modified based on the third signal. The machine also includes a throttle / accelerator pedal lock feature, which allows the operator to lock the engine speed at a desired level while allowing independent control of the continuously variable transmission. The throttle lock feature allows the machine to be operated without manual operation of the right foot pedal.

[0005] Although the system of patent 681 can provide efficient control of a continuously variable transmission, it may still be less than optimal. In particular, it still requires the operator to adjust or modulate the left foot pedal during operation, which can be cumbersome and tiring. Additionally, there may be times when the engine speed selected by the operator (i.e., the engine speed selected via the accelerator pedal lock feature) is inefficient for current operations, and the system of patent 681 provides no means of overriding this feature.

[0006] Furthermore, US 2010 / 0 174 456 A1 discloses a mechanical CVT drivetrain and a control method for internal combustion engine earthmoving vehicles. The drivetrain establishes a propulsion relationship between the internal combustion engine and the wheels of the earthmoving vehicle. It has a manual control unit to select between a first and a second operating mode, the first mode corresponding to a command to move the vehicle forward and the second mode corresponding to a command to move the vehicle backward. The vehicle has an electronic control unit. While in motion, it responds to a change in operating mode made via the control unit, indicating a command to reverse the vehicle's direction of travel, in order to send a control signal to the mechanical CVT transmission to cause it to downshift.

[0007] DE 11 2008 003 259 T5 discloses a vehicle drive force control device, wherein a switching output torque control unit performs switching output torque control to control a power engine torque in order to reduce a drive force differential, which is a variation in drive force due to downshifting of an automatic transmission. DE 11 2008 002 625 T5 teaches a control system for a continuously variable transmission, in particular a torque-based control system for a continuously variable transmission. US 2008 / 0234102 A1 discloses a method and an arrangement for adapting shifting strategies in a heavy vehicle with an automated transmission and power take-off (PTO) load.US 4 414 863 A discloses an automatic electronic control for a power shift transmission, wherein a control unit with a microprocessor is provided for automatic shifting of a transmission and for selective locking and unlocking of a torque converter connecting the engine to the transmission.

[0008] The powertrain control system of the present disclosure solves one or more of the problems set out above and / or other prior art problems. Summary

[0009] The object of the present invention is achieved by a drive train control system for a mobile machine according to claim 1. The dependent claims relate to preferred embodiments of the invention. Brief description of the drawings Fig. Figure 1 is a diagram-like representation of an exemplary disclosed machine; Fig. Figure 2 is a pictorial representation of an exemplary disclosed operator station, which is used in conjunction with the machine of the Fig. 1 can be used; Fig. 3 is a diagram-like representation of an exemplary disclosed powertrain control system, which, in conjunction with the machine of the Fig. 1 can be used; and Fig. Figure 4 is a flowchart illustrating an exemplary disclosed operation controlled by the powertrain control system of the Fig. 3 can be carried out. Detailed description

[0010] Fig. Figure 1 illustrates an exemplary machine 10 with several systems and components that work together to perform a task. The tasks performed by machine 10 can be associated with a particular industry, such as mining, construction, agriculture, transportation, energy production, or any other industry known in engineering. For example, machine 10 can represent a mobile machine, such as a wheel loader, which operates in Fig. Figure 1 shows a bus, a road or off-road transport vehicle, or any other type of mobile machine known in the art. The machine 10 comprises a frame 11, an operator station 12 supported by the frame 11, one or more traction devices 14 rotatably connected to the frame 11, and a drive train 16 supported by the frame 11 and operationally connected to drive at least one of the traction devices 14 in response to an input received from the operator station 12.

[0011] As in Fig. As illustrated in Figure 2, the operator station 12 can be a generally enclosed cabin with devices that receive manual signals indicating a desired machine movement. In particular, the operator station 12 can have one or more interface devices 18 located near an operator seat 20. Interface devices 18 can initiate movement and / or activate features of the machine 10 by generating signals indicating a desired machine function. In one embodiment, interface devices 18 can include a left foot pedal 18a, a right foot pedal 18b, and a feature selection device 18c. When an operator actsuates the left foot pedal 18a and / or the right foot pedal 18b (i.e., moves the left and / or right foot pedal 18a, 18b from a neutral position), the operator can expect and influence a corresponding machine movement function.When the operator manipulates or operates the feature selection device 18c, the operator can select the activation of a specific control feature (e.g., a drivetrain locking feature). It is considered that interface devices other than foot pedals and feature selection devices, such as joysticks, levers, switches, buttons or handles, wheels, and other devices known in the art, may be provided additionally or alternatively within the operator station 12 for the travel control of the machine 10, if desired.

[0012] Traction devices 14 (with reference to Fig. 1) The traction devices can be wheels arranged on each side of the machine 10 (only one side is shown). Alternatively, the traction devices 14 can include tracks, belts, or any other known traction devices. It is considered that any combination of wheels on the machine 10 can be driven and / or steered.

[0013] As in Fig. As illustrated in Figure 3, the drivetrain 16 can be an integral unit configured to generate power and transmit it to the traction devices 14. In particular, the drivetrain 16 can include a motor 22, hereinafter also referred to as the main motor 22, which is operable to generate a power output, a gearbox 24 which is connected to receive the power output and transmit the power output usefully to the traction devices 14 (with reference to Fig. 1) to transmit, and a control system 26 configured to control the operation of the main motor 22 and the transmission 24 responding to one or more signals generated by the left foot pedal 18a, the right foot pedal 18b, the feature selection device 18c and one or more different sensors.

[0014] The main engine 22 can be an internal combustion engine having several subsystems that work together to generate a mechanical and / or electrical power output. For the purposes of this disclosure, the engine or main engine 22 is shown and described as a four-stroke diesel engine. However, those skilled in the art will recognize that the main engine 22 can be any other type of internal combustion engine, such as a gasoline engine or a gaseous fuel-powered engine. The subsystems included within the main engine 22 can include, for example, a fuel system, an air intake system, an exhaust system, a lubrication system, a cooling system, and other suitable systems.

[0015] The main motor 22 can be controlled, at least partially, by the right foot pedals 18b. That is, when a right foot pedal 18b is actuated by an operator, it can generate an electrical signal directed to a control device 36 of the control system 26, indicating a desired motor speed. For example, the right foot pedal 18b can have a minimum position corresponding to a low idle speed of the main motor 22 and can be movable through a range of positions to a maximum position corresponding to a rated speed of the main motor 22. A sensor 38, such as a switch or potentiometer, can be provided in conjunction with the right foot pedal 18b to sense its displacement position and generate a corresponding signal in response to the displacement.The displacement signal from sensor 38 can be routed by the control device 36 to the main engine 22 (e.g., to the fuel system, the air intake system, the exhaust system, or another system of the main engine 22) to control the speed of the main engine 22. Although the main engine 22 has been described as a low-idle engine (i.e., the minimum displacement position of the right foot pedal 18b is associated with a low idle speed of the main engine 22), it is considered that the main engine 22 could alternatively be a high-idle engine (i.e., the minimum displacement position of the right foot pedal 18b could be associated with a high idle speed of the main engine 22, and furthermore, displacement of the right foot pedal 18b could lead to a reduction in engine speed) if desired.

[0016] A sensor 28 can be associated with the main motor 22 to sense its rotational speed. For example, the sensor 28 can be a magnetic transducer type associated with a magnet embedded within a rotating component of the drivetrain 16, such as a crankshaft or flywheel of the main motor 22. During operation of the main motor 22, the sensor 28 can sense the rotating field generated by the magnet and can produce a signal corresponding to the rotational speed of the main motor 22.

[0017] The transmission 24 can, for example, represent a continuously variable transmission (CVT). Transmission 24 can be any type of continuously variable transmission, such as a hydraulic continuously variable transmission, a hydromechanical continuously variable transmission, an electric continuously variable transmission, an electromechanical continuously variable transmission, a hydraulic or electric continuously variable transmission in parallel, or any other configuration, as would be obvious to a person skilled in the art.

[0018] A continuously variable transmission generally consists of a drive element 30 and a driven element 32, which is hydraulically, electrically, and / or mechanically connected to the drive element 30. In the simplified, exemplary hydraulic continuously variable transmission of the Fig. In Figure 3, the drive element 30 is a hydraulic pump, such as a bidirectional piston-type hydraulic pump with variable displacement (i.e., an over-center pump). However, it is considered that the drive element 30 could alternatively be a unidirectional pump, a fixed-displacement pump, or a rotary pump (or an electric generator, such as in an electric or electromechanical continuously variable transmission), if desired. In the same configuration, the driven element 32 is shown as a hydraulic motor, such as a bidirectional piston motor with variable displacement.Similar to the drive element 30, the driven element 32 can alternatively be a unidirectional motor, a fixed-displacement motor, or a rotary motor (or an electric motor, such as in an electric or electromechanical continuously variable transmission), if desired. The drive element 30 can be connected to supply power to the driven element 32 via a pressurized fluid through an open or closed circuit 34, responding to displacement commands directed to the driving and / or driven elements 30, 32. In some situations, the driven element 32 can alternatively supply power to the driving element or drive element 30 in the reverse direction, for example, during braking of machine 10.

[0019] The transmission 24 can be controlled, at least partially, by left and right foot pedals 18a and 18b. That is, when the operator presses the right foot pedal 18b, the signal generated by the right foot pedal 18a can indicate a desired output torque of the transmission 24, in addition to the desired engine speed. Therefore, the greater the displacement of the right foot pedal 18b, the greater the output torque of the transmission 24. Conversely, when the operator presses the left foot pedal 18a, the left foot pedal 18a can generate a signal directed to the control device 36 indicating a desired reduction in the transmission output torque.

[0020] For example, the left foot pedal 18a can have a minimum position corresponding to a maximum torque output of the gearbox 24 (i.e., no reduction in output torque is requested by the right foot pedal 18b), and can be movable over a range of positions up to a maximum position corresponding to a minimum torque output (i.e., a maximum reduction in the gearbox output torque). A sensor 40, such as a switch or a potentiometer, can be provided in conjunction with the left foot pedal 18a to sense its displacement position and generate a corresponding signal in response to the displacement. The displacement signal from the sensor 40 can be transmitted by the control device 36 to the gearbox 24 to control the torque output of the driving and / or driven elements 30, 32 by adjusting their displacement(s).In one embodiment, the signal generated by sensor 40 can have a value corresponding to a percentage of a permissible torque output available for a current rotational speed of machine 10.

[0021] In some embodiments, the left foot pedal 18a can also be associated with braking a traction device 14. In these embodiments, the left foot pedal 18a can be moved from its minimum displacement position, through an intermediate threshold position, to its maximum displacement position. As described above, the minimum displacement position of the left foot pedal 18a can be associated with the maximum torque output of the transmission 24. In contrast to the embodiment described above, however, in this embodiment the left foot pedal 18a can alternatively generate a signal indicating the minimum torque output of the transmission 24 at the intermediate threshold position. Further displacement of the left foot pedal 18a from the intermediate threshold position can then result in an increase in the braking of the traction device 14.

[0022] A sensor 42 can be connected to the transmission 24 and / or the traction device 14 (with reference to Fig. 1) be associated with sensing the travel speed of the machine 10. In one example, the sensor 42 can be a magnetic transducer type sensor associated with a magnet embedded within a rotating component of the drive train 16, such as a transmission output shaft. During operation of the machine 10, the sensor 42 can sense the rotating field generated by the magnet and can generate a signal corresponding to the rotational speed of the transmission 24 and / or the corresponding travel speed of the machine 10.

[0023] The control device 36, together with the interface devices 18, the sensors 40 and 42, the (not shown) control components of the main motor 22, and the displacement control mechanisms of the transmission 24, can form the control system 26. The control device 36 can embody a single microprocessor or multiple microprocessors, which have means for controlling the operation of the drive train 16 in response to the received signals. Numerous commercially available microprocessors can be configured to perform the functions of the control device 36. It should be clear that the control device 36 could easily embody a general-purpose machine processor capable of controlling numerous machine functions. The control device 36 can include a memory, a secondary memory device, a processor, and any other components necessary for carrying out an application.Various other circuits may be associated with the control device 36, such as a power supply circuit, signal conditioning circuit, electromagnetic driver circuit, or other types of circuits.

[0024] One or more transmission control plans or maps relating to the displacement of the left foot pedal, the displacement of the right foot pedal, the status of the feature selection device 18c, the detected vehicle speed, the desired vehicle speed, the desired engine speed, the desired torque output, the torque output command, the torque output limits, and / or other control variables can be stored within the memory of the control device 36. Each of these plans or maps can be in the form of tables, graphs, and / or equations and can contain a compilation of data collected in the laboratory and / or during field operation in the powertrain 16. The control device 36 can access these plans or maps.It refers to characteristic maps and can control the main motor 22 and the gearbox 24 to align the operation of the drive train 16 with the expected and / or desired performance characteristics of machine 10.

[0025] Fig. Figure 4 shows an exemplary method for controlling the drive train 16, which is regulated by the control device 36. Fig. 4 will be discussed in more detail in the following section to clarify further aspects of the revealed system. Industrial applicability

[0026] The disclosed powertrain control system can be applied to any mobile machine that has a continuously variable transmission. The disclosed powertrain control system can provide improved efficiency and control of the associated powertrain while also reducing operator effort. The operation of the powertrain control system 26 will now be described in detail with reference to Fig. 4 described.

[0027] As shown in the flowchart in Fig.As illustrated in Figure 4, the first step in controlling the drive train 16 can involve monitoring the status of the interface devices 18. In particular, the control device 36 can monitor the displacement position of the left foot pedal 18a, the displacement position of the right foot pedal 18b, and the actuation of the feature selection device 18c (step 400). From the displacement signals received via sensors 40 and 42, the control device 36 can determine a desired rotational speed of the main motor 22 and a desired output torque of the gearbox 24 (i.e., a desired percentage of a permissible output torque for the current travel speed of the machine 10).Based on these desired values, the control device 36 can then make adjustments to the main engine 22 and the transmission 24 to reduce any difference between the actual engine speed and the desired engine speed, and any difference between the actual torque output and the desired torque output (step 405). The engine speed can be adjusted by settings of the fuel system, the air intake system, the exhaust system, or any combination of these settings. The transmission output torque can be adjusted by setting (i.e., displacement or displacement setting) one of the drive element 30 and the driven element 32, or both.

[0028] The control device 36 can also determine whether a feature selection device 18c has been actuated by the operator of machine 10 (step 410). If the feature selection device 18c has not been actuated, the control can return to step 400. However, if the feature selection device 18c has been actuated by the operator of machine 10, the control device 36 can then lock the speed of the main motor 22 at the current motor speed (step 415). For example, the operator can depress the right foot pedal 18b until a desired motor speed is reached and can then actuate the feature selection device 18c to lock that motor speed for use in performing a specific task.Locking the speed of the main motor 22 eliminates the need for the operator to operate the right foot pedal 18b, allowing the operator to focus their efforts on other, more critical tasks. This can help reduce operator fatigue. Additionally, the speed selected by the operator may be one known to them as the most efficient or best-controllable speed for the specific task.

[0029] Actuation of the feature selection device 18c can also trigger the control device 36 to lock the output torque of the gearbox 24 (step 420). In particular, upon locking the motor speed, the control device 36 can lock the output torque at a specific percentage of an available output torque for the current travel speed of the machine 10. The percentage value can be determined via one or more lookup maps or characteristic maps stored as a function of the locked motor speed. For example, for a locked motor speed of approximately 50% of the rated speed at a current travel speed of 8 km / h, the control device 36 can lock a torque output of the gearbox 24 at approximately 50% of the maximum torque permissible at 8 km / h.If the travel speed of the machine 10 varies, the value of the output torque of the gearbox 24 can also vary (along with variations in the maximum size of permissible torque), but can remain locked at approximately 50% of the maximum size of permissible torque.

[0030] At any time during the operation of machine 10, the operator can choose to adjust the motor speed and / or the transmission output torque differently from the locked values, either temporarily or permanently. In particular, the control device 36 can continuously monitor the displacement positions of the left and right foot pedals 18a, 18b to determine whether such a deviation is desired and what type of deviation is desired (step 425). If the operator moves the right foot pedal 18b to increase the motor speed (i.e.,If the control device 36 detects a displacement of the right foot pedal 18b to a position corresponding to an engine speed greater than the locked engine speed (step 328), then the control device 36 can allow a temporary override of the locked engine speed (step 430) and can engage an engine speed corresponding to the displacement position of the right foot pedal 18b. As soon as the operator releases the right foot pedal 18b, the control device 36 can return the speed of the main motor 22 to the previously locked value, as long as the feature actuation device 18c is still active. That is, the control can run back from step 430 through steps 410-420. It should be noted that actuation of the right foot pedal 18b to a position corresponding to an engine speed less than the locked engine speed (step 328: No) may have no effect on the control of the drive train 16.

[0031] When the operator depresses the left foot pedal 18a, the control device 36 can compare the displacement position with a threshold value before proceeding (step 435). If the left foot pedal 18a has been moved to a position less than a threshold position (step 435: No), then the control device can proceed to step 430, allowing temporary override of the transmission output torque in the same manner as described above for the engine speed. However, if at step 435 the control device 36 determines that the left foot pedal 18a has been moved by at least a threshold value (step 435: Yes), then the control device 36 can instead terminate the operations with locked speed and locked torque (step 440) and the control device can return to step 400.In one embodiment, the threshold value can be at least 75% of the range from the minimum displacement position to the maximum displacement position. In another embodiment, the threshold value can be approximately equal to the intermediate displacement position at which the braking of the traction devices 14 is activated or actuated. It is considered that in some applications, the left foot pedal 18a may need to be displaced by the threshold value for at least one threshold duration before the locked speed and locked torque operations are released. In these applications, the threshold duration can be a function of the machine travel speed.

[0032] Returning to step 425, during a control operation with locked speed and locked torque (i.e., when the operator has not moved the left or right foot pedals 18a, 18b), the control device 36 can continuously compare the current travel speed of the machine 10 with a travel speed threshold (step 445). In an exemplary embodiment, the travel speed threshold can be associated with a speed at which the machine 10 is most likely to travel long distances between locations at a work site or even between work sites. At this speed, machine functions not related to movement (e.g., tool functions) generally cannot be used. In the disclosed embodiment, the travel speed threshold can be approximately 20 km / h.In other embodiments, the travel speed threshold can be variable and can be at least partially at a travel speed limit selected by the operator. If the control device 36 determines that the travel speed of the machine 10 is lower than the threshold speed, the control can return to step 410 without taking any further action.

[0033] However, if the control device 36 determines at step 445 that the current travel speed of machine 10 is greater than the threshold travel speed, the control device 36 can conclude that the operator of machine 10 is highly unlikely to request the activation or operation of functions unrelated to movement, and can then determine whether a more efficient engine speed is available (step 450). That is, the control device 36 can determine whether a main engine 22 can be operated at a lower speed (i.e., at a speed that requires less fuel) and still drive machine 10 at the same travel speed. If such a speed is not available, the control device can return to step 410.However, if a more efficient speed is available, the control device 36 can override the speed locked by the operator and can reduce the speed of the main motor 22 (step 455).

[0034] Reducing the engine speed without adjusting the gearbox 24 can lead to a deviation from the current travel speed of the machine 10. Accordingly, the control device 36 can adjust the gear ratio of the gearbox 24 at approximately the same time as the speed of the main engine 22 is adjusted, so that the travel speed of machine 10 remains essentially constant.

[0035] After reducing the speed of the main motor 22, the control device 36 can monitor the operation of the main motor 22 to determine whether it is generating power at a level lower than that required by current conditions or by the operator. Specifically, the control device 36 will compare the travel speed of machine 10 with a minimum threshold travel speed (step 460). If the control device 36 determines that the machine 10 is traveling at a speed lower than the minimum travel speed, it can reduce the speed of the main motor 22 to the previously locked value (step 465), and the control can return to step 410. This situation can occur, for example, if the machine 10 is traveling at a relatively high speed (e.g.,(Above approximately 20 km / h), when the control device 36 reduces the speed of the main motor 22 to a more efficient level, and then the operator activates or operates a function unrelated to movement (e.g., the operator operates the tooling system of the machine 10). In this situation, a power demand may be made on the main motor 22 that cannot be supplied by the main motor 22 at the current travel speed, and therefore the travel speed falls below the minimum threshold travel speed. Accordingly, in this situation, the control device 36 can increase the speed of the main motor 22 back to the previously locked value.

[0036] In some embodiments, the control of the drive train 16 can be influenced by the actuation of a parking brake (not shown). For example, it is considered that if the feature selection device 18c is actuated at the same time as the parking brake is applied, only the speed of the main motor 22 is locked. In contrast, if the parking brake is not active, both the speed of the main motor 22 and the torque output of the transmission 24 can be locked. Additionally, if the status of the parking brake changes (i.e., if the parking brake is engaged or disengaged) while the feature selection device 18c is engaged, the control device 36 can respond to this change and disengage the feature selection device 18c.

[0037] The drivetrain control system 26 can provide improved efficiency through demand-driven, automated control of engine speed and transmission output torque. That is, by using operator-locked engine speed and transmission output torque and selectively and automatically overriding these locked values ​​at opportune times, the efficiency of machine 10 can be improved. The drivetrain control system 26 can also provide improved control over the drivetrain 16. In particular, the ability to temporarily deviate from the locked engine speed and transmission output torque and then quickly return to them can equip the operator with the ability to precisely match the short-term power supply to short-term power demands while maintaining the overall operation of the machine at levels that are efficient in the long run.Additionally, the ability to lock not only the motor speed but also the transmission output torque can help reduce operator effort and fatigue. This means that the operator does not need to constantly operate the left foot pedal 18a and the right foot pedal 18b while operating machine 10, thus requiring less physical exertion and causing fewer distractions from more important tasks.

Claims

[1] Powertrain control system (26) for a mobile machine (10) comprising the following: a motor (22); a continuously variable transmission (24) which is operationally coupled to the motor (22); an operator input device (18b) configured to generate a signal indicating a desired speed of the motor (22); a feature selection device (18c) which can be used by an operator to select an actuation of a powertrain control feature; a control device (36) that communicates with the motor (22), the continuously variable transmission (24), the operator input device (18b) and the feature selection device (18c), wherein the control device (36) is configured to: Performing a determination that the operator has selected an actuation of the powertrain control feature via the feature selection device (18c); Locking a speed of the motor (22) based on the determination and the signal; Locking a torque output of the continuously variable transmission (24) based on the determination and locked speed of the motor (22); and Locking the torque output of the continuously variable transmission (24) at a percentage of a maximum available torque for a given travel speed of an associated mobile machine (10); wherein the percentage at which the torque output of the continuously variable transmission (24) is locked is based on the locked speed of the motor (22); and wherein the powertrain control system further includes a vehicle speed sensor (42) which is configured to generate a signal, which displays a travel speed of the mobile machine (10), wherein the control device (36) is connected to the travel speed sensor (42), wherein the control device (36) is further configured to: Determine, based on the signal from the travel speed sensor (42), that a current travel speed of the mobile machine (10) is associated with high-speed movement, while machine functions not related to movement are not used; and respond to this, reduce the speed of the engine (22) below the locked speed to a more fuel-efficient speed. [2] Powertrain control system (26) according to claim 1, wherein the control device (36) is further configured to selectively adjust the torque output of the continuously variable transmission (24) during a reduction in the speed of the motor (22), so that a substantially constant driving speed of the mobile machine (10) is maintained during the reduction. [3] Powertrain control system (26) according to claim 1, wherein the control device (36) is further configured to reduce the speed of the motor (22) to the locked speed when the current driving speed falls below a threshold. [4] Powertrain control system (26) according to claim 1, wherein: the operator input device (18b) is a first pedal arranged inside an operator cabin (12) of a mobile machine (10); the signal from the first pedal (18b) further indicates a desired output torque of the continuously variable transmission (24); and the powertrain control system further comprises a second pedal (18a) located and configured in the operator cabin (12), to generate a signal indicating a desired reduction in the output torque of the continuously variable transmission (24). [5] Powertrain control system (26) according to claim 4, wherein: Actuation of the first pedal (18b) temporarily overrides the locked speed of the motor (22) and the locked torque output of the continuously variable transmission (24); and The actuation of the second pedal (18a) temporarily overrides the locked torque output of the continuously variable transmission (24). [6] Powertrain control system (26) according to claim 5, wherein: the temporary oversteer caused by the actuation of the first pedal (18b) exhibits only a temporary increase in the locked speed and locked output torque; and the temporary oversteer caused by the actuation of the second pedal (18a) only exhibits a temporary reduction in the locked torque output. [7] Powertrain control system (26) according to claim 1, wherein the control device (36) is configured to: Locking only the speed of the motor (22) when a parking brake of the mobile machine (10) is active; Locking the speed of the motor (22) and the torque output of the continuously variable transmission (24) when the parking brake is inactive; and Terminating the locking of the motor speed (22) and the torque output of the continuously variable transmission (24) when a parking brake status changes.

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