Abstract:
A speed change control system for reducing shift shocks of clutch-to-clutch shifting is provided. The control system is applied to a vehicle in which a transmission having engagement devices is connected to an output side of a prime mover, and in which a gear stage of the transmission is shifted among a plurality of stages by changing engagement states of the engagement devices. The speed change control system carries out a clutch-to-clutch shifting from a predetermined gear stage to another gear stage by reducing a torque capacity of the predetermined engagement device to be disengaged while increasing a torque capacity of another engagement device to be engaged.
Abstract:
A method for shifting gears in a dual clutch transmission within a motor vehicle and a motor vehicle implementing said method are suggested providing a smooth transition between gears particularly in the starting phase. The dual clutch transmission comprises a first clutch and a second clutch as well as a first partial transmission having a first and other gears and a second partial transmission having a second and other gears. The clutches are controlled to a) decrease a torque transmitting capacity of the first clutch; b) increase a torque transmitting capacity of the second clutch; c) adapt the rotational speed of the motor in direction of a rotational speed of an input shaft of the second partial transmission via increasing the torque transmitting capacity of the second clutch; and d) control the torque transmitting capacity of the second clutch to a final torque value.
Abstract:
A method for controlling a powertrain includes operating a transmission in a neutral operating range state, monitoring commands affecting an input speed, monitoring a tracked clutch slip speed, determining constraints on an input acceleration based upon the commands, determining a clutch slip acceleration profile based upon the constraints on the input acceleration, determining an input acceleration profile based upon the clutch slip acceleration profile, and controlling the powertrain based upon the clutch slip acceleration profile and the input acceleration profile.
Abstract:
A method of performing a directional shifting event in a hydrostatic drive work machine, and a hydrostatic drive work machine is provided. The method includes the step of adjusting a pump displacement of a variable displacement pump coupled with an engine and a hydraulic motor of the work machine, at a rate based at least in part on one or both of a predetermined acceleration limit and a predetermined jerk limit of the work machine. The work machine includes an electronic control module having a computer readable medium with a directional shifting control algorithm recorded thereon. The control algorithm is operable to adjust a pump displacement in a hydrostatic drive of the work machine at a rate based at least in part on one or both of the predetermined acceleration limit or jerk limit of the work machine.
Abstract:
A continuously variable transmission is controlled using a target acceleration map which contains values of target accelerations corresponding to a plurality of values of a first indication (e.g., the amount of depression of an accelerator pedal or the engine throttle opening) representative of the driver's intention for acceleration or deceleration and a plurality of values of a second indication representative of speeds of the motor vehicle. The target acceleration map is arranged such that when each of the values of the second indication is constant, each of the values of the target acceleration increases as the value of the first indication increases, at a rate which is greater if the first indication is smaller. From such a target acceleration map, a target acceleration is determined on the basis of the actual values of the values of the first and second indications at the time, and the speed reduction ratio of the transmission is controlled so that the target acceleration is achieved. In the target acceleration map, the cruising speed of the motor vehicle varies linearly as the values of the first indication vary.
Abstract:
A method for controlling a preferably electrohydraulically actuated continuously variable transmission of a motor vehicle equipped with an internal combustion engine provides, in and ahead of curves, a retention of the last gear ratio set. The gear-ratio determination is initiated when the accelerator pedal is released rapidly in coasting operation. The gear transmission determination is suspended as soon as, after expiration of a time interval following recognition of acceleration, no curve is being traversed. If, during expiration of the time interval, coasting operation is detected again, the gear transmission determination is maintained for an additional time interval. Upon termination of the gear-ratio determination, a relatively slow adaptation of the gear ratio to the setting corresponding to the control curve RKLj takes place.
Abstract:
A method reduces a time delay or lag between a commanded upshift and a resultant upshift event in vehicle. The method detects the commanded upshift, calculates a scheduled engine torque reduction torque value as a function of an unmanaged torque, and reduces an input torque value from the engine using the calculated scheduled torque. A powertain includes an engine, a transmission, a torque converter, clutches that are selectively engageable to provide at least six forward speed ratios, a reverse speed ratio, and a neutral condition, and a controller. The controller has an algorithm controlling an operation of an off-going clutch and the on-coming clutch during a speed ratio change representing an upshift event. The algorithm calculates a scheduled torque value as a percentage of an unmanaged torque level of the engine, and controls the off-going and on-coming clutch through the speed ratio change using the calculated scheduled torque value.
Abstract:
A control device for a vehicle which includes a differential portion controlling a differential state between the number of rotations of an input shaft connected to an engine, and the number of rotations of an output shaft connected to drive wheels, with controlling an operating state of an electric motor, and an automatic shifting portion forming part of a power transmitting path. The control device prevents degradation in operability of the vehicle, even in the presence of a shifting command resulting from a manual shift operation when the automatic shifting portion remains under a limited shifting state. More particularly, if the shifting command is present due to the manual shift operation, the differential state of the differential portion is controlled, thereby causing a variation in a drive force at a rate corresponding to the shifting command.
Abstract:
A controlling system for a vehicle with a continuously variable transmission, which can render a sufficient accelerating feeling in responsive to a driver's requirement. A controller, upon judgment of an acceleration requirement, sets a target drive force higher than the target drive force upon normal calculation upon normal operation of an accelerator pedal, and sets a target rotation speed for acceleration higher than the target rotation speed upon the normal operation and increasing with an increase of the vehicle speed by a predetermined gradient. The speed change ratio of the continuously variable transmission and the output torque of the engine are controlled such that the set target drive force is achieved, and an input shaft rotation speed of the continuously variable transmission coincides with the target rotation speed for the set acceleration. Thus, upon acceleration requirement by the driver, the target drive force increases and the output rotation speed of the drive source increases so that the sufficiently high accelerating feeling from the vehicle can be obtained.
Abstract:
A method reduces a time delay or lag between a commanded upshift and a resultant upshift event in vehicle. The method detects the commanded upshift, calculates a scheduled engine torque reduction torque value as a function of an unmanaged torque, and reduces an input torque value from the engine using the calculated scheduled torque. A powertain includes an engine, a transmission, a torque converter, clutches that are selectively engageable to provide at least six forward speed ratios, a reverse speed ratio, and a neutral condition, and a controller. The controller has an algorithm controlling an operation of an off-going clutch and the on-coming clutch during a speed ratio change representing an upshift event. The algorithm calculates a scheduled torque value as a percentage of an unmanaged torque level of the engine, and controls the off-going and on-coming clutch through the speed ratio change using the calculated scheduled torque value.