Abstract: Aspects of the disclosure relate to controlling a vehicle in an autonomous driving mode. For instance, a trajectory is identified. The trajectory defines a future desired path for the vehicle and includes a control requirement having a corresponding point in time. A command for achieving the control requirement is generated. A fixed delay value corresponding to a delay caused by transmission of the command to an actuator of the vehicle is generated. A variable delay value corresponding to a delay caused by an amount of time to change a physical state of the actuator to a desired state according to the command is generated. The command is then sent to the actuator based on the fixed delay value, the variable delay value, and so that the actuator causes the vehicle to move according to the command.

Abstract: A drive train control method includes transmitting a total time period of a stroke phase and a torque phase of an upshift from a transmission control unit of an automatic transmission to an engine control unit of an engine. The method also includes closing a first shift element of the automatic transmission and opening a second shift element of the automatic transmission during the upshift. A control pressure of the first shift element increases during the torque phase relative to the control pressure of the first shift element at an end of the stroke phase. A control pressure of the second shift element decreases during the torque phase relative to the control pressure of the second shift element at the end of the stroke phase. The method further includes, based at least in part on the total time period of the stroke and torque phases, increasing an actual torque of the engine during the upshift such that the actual torque of the engine increases to a higher gear torque prior to an end of the torque phase.

Abstract: There is provided an automatic transmission capable of preventing deterioration of driving performance even when an engagement mechanism is not switched due to a failure. An automatic transmission includes a first brake which is always in a fixed state from a first forward gear stage to a predetermined gear stage and is in an open state at a gear stage with a higher speed than the predetermined gear stage, and a hydraulic sensor configured to detect whether the first brake is switched to the fixed state. When a transmission control device instructs the first brake to switch to the fixed state, and it is confirmed that the first brake is in an open state, the transmission control device instructs engagement mechanisms other than the first brake to perform switching so that a preliminary gear stage is able to be set.

Abstract: A method of down-shifting a transmission avoids output shaft oscillations by briefly increasing the torque capacity of an off-going element at the end of the inertia phase. The torque capacity of the off-going element is then reduced to zero when the measured transmission speed ratio begins to decrease. The method is suitable for downshifts that involve multiple off-going elements and multiple on-coming elements such as a shift from tenth gear to sixth gear in a ten speed transmission.

Abstract: Features for varying speeds available and/or range of operation of transmissions are provided for use in high performance, increased efficiency, and/or other applications. Increased performance and/or efficiency may be obtained by using additional speeds or gear ranges to maintain drivetrain operation within maximum power and/or efficiency bands of internal combustion engine operation.

Abstract: A control system for a hybrid drive unit includes a pressure regulator valve, a first variable bleed solenoid valve for controlling a stationary clutch and a second variable bleed solenoid valve for controlling a rotating clutch. The control system controls the stationary clutch and the rotating clutch to operate the hybrid drive unit in four different modes.

Abstract: The present invention is related to a method of controlling a device having a calibration process. The calibration process has a partial calibration routine and a calibration routine. A detector within the control system is capable of receiving one or more input signals and determining whether a partial calibration or calibration should occur. The first step in the process involves starting the control method where the detector receives input signals or generates it own data within the detector. The detector also determines whether a partial calibration routine or a calibration routine will take place based upon the value of the input signals received. A partial calibration routine will be performed if the input signals to the detector do not favor a calibration.

Abstract: Interruption in supervisory position control signals can cause problems with respect to actuators which upon loss of such control signals for the actuator will generally slew to a fixed idle position. In such circumstances a machine such as a gas turbine engine in which an actuator is associated will not sustain performance even though there is continued local power supply to the actuator. By utilizing a local controller which stores actuator response profiles for certain machine status stages through perturbation or marginal activation of the actuator an appropriate actuator response profile can be chosen and therefore sustaining control signals presented to the actuator to maintain machine operation.

Abstract: A vehicle drive unit is provided which includes a hydraulic circuit capable of efficiently supplying a hydraulic pressure from an accumulator to a hydraulic servo while minimizing the capacity of the accumulator. In a hydraulic circuit included in a continuously variable transmission, an accumulator is connected through an electromagnetic switch valve to an oil passage connecting a clutch pressure control valve and a manual valve, a one-way valve for allowing oil to flow only in the direction from the clutch pressure control valve toward the accumulator and the forward clutch is provided in the oil passage. The electromagnetic switch valve switches an oil passage to a communicating state when the oil pump is driven and switches the oil passage to a shut-off state when the oil pump is stopped.

Abstract: The present invention provides a method and apparatus for adaptively controlling a closed throttle downshift in an automatic transmission wherein a transmission aberration during a shift is diagnosed and corrected during subsequent closed throttle downshifts. The invention is carried out by monitoring transmission characteristics including input speed, output speed and shift duration during a closed throttle downshift, and identifying departures from acceptable patterns. Each type of departure calls for a particular remedy, and a suitable adjustment is calculated based on the times and/or the commanded pressures at certain times, the adjustment being implemented by changing one or more initial conditions for the next shift of the same type. The adjustments may have to be large to make a full or significant partial correction at the next shift. Conversely small increments may be necessary to avoid over-correction.

Abstract: Whenever a 4 to 3 shift condition is satisfied during a 3 to 4 upshift, 4 to 3 shifting is started before the 3 to 4 shifting is finished. The 4 to 3 shifting is executed according to a predetermined hydraulic control pattern. Therefore, responsiveness in shifting is enhanced.

Abstract: An apparatus for controlling a vehicle automatic transmission having a hydraulically operated frictional coupling device operable to effect a shifting action of the automatic transmission, and an accumulator connected to the frictional coupling device, the apparatus including an accumulator-back-pressure learning compensation device operable to effect learning compensation of a back pressure of the accumulator such that an actual value of a rate of change of a rotating speed of a selected rotary element of the automatic transmission, which rotating speed changes as a result of the shifting action, approaches a predetermined target value, and an accumulator-back-pressure control device operable to control the back pressure, on the basis of an output of the accumulator-back-pressure leaning compensation device, whereby a shifting shock of the transmission can be reduced.

Abstract: An automatic control strategy for use with a multiple-ratio transmission in an automotive vehicle driveline in which the crankshaft of an internal combustion engine is connected directly to torque input elements of multiple-ratio gearing without an intervening hydrokinetic torque converter. The strategy is adapted especially for use with a wet auto clutch to provide forward or reverse drive engagement during vehicle launch and during transient damping of driveline disturbances. The strategy makes it possible to control the clutches to achieve maximum vehicle acceleration by controlling the engine speed so that it operates at maximum torque throughout the useful engine speed range for any given engine throttle position. The entry and exit conditions for each drive mode are determined by the strategy so that optimum drive-away performance and optimum shift control, as well as soft clutch engagement and full clutch engagement, can be achieved.

Abstract: A downshift control device for an automatic transmission is provided in which the transmission is shifted down by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released. This downshift control device determines whether a downshift command is generated to shift down the transmission while an accelerator pedal is being depressed, and detects a gear ratio that changes during the pedal-depressed downshift control. First control actuator controls the back pressure of a first accumulator provided in an oil path leading to the first engaging element, and second control actuator controls back pressure of a second accumulator provided in an oil path leading to the second engaging element.

Abstract: A downshift control device for an automatic transmission is provided in which the transmission is shifted down by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released. This downshift control device includes an applied pressure control actuator for controlling a pressure to be applied to the second engaging element, by supplying a pressurized oil to a back pressure chamber of an accumulator provided in an oil path to the second engaging element, and removing the pressurized oil from the back pressure chamber.

Abstract: A downshift control device for an automatic transmission is provided in which the transmission is shifted down by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released.

Abstract: A speed change control method for an automatic transmission is provided, which is capable of reducing a shift shock and a required shifting time period. A skip down-shift from a first shift position to a second shift position is effected by way of a third shift position which is not used in a normal shifting. If it is determined that a difference (N.sub.TM -N.sub.T) between the present turbine rotation speed N.sub.T and the synchronous rotation speed N.sub.TM for the third shift position becomes smaller than a threshold value .DELTA.N.sub.FM during the shifting from the first shift position to the third shift position, a control for releasing a friction engaging element 23, corresponding to a releasing side speed-changing element of the third shift position, is started prior to establishment of the third shift position, whereby a time period for establishing the third shift position is shortened, so that a shift shock and a required shifting time period are reduced.

Abstract: A control system is provided for servo hydraulic pressure in an automatic transmission. Upon downshifting, one of first and second frictional engagement devices is released while the other is engaged. A directional control valve is provided to feed or drain servo hydraulic pressure to selectively engage or release the first and second devices. The hydraulic pressure is regulated by a pressure regulator under the control of an electronic control unit. Detectors are also provided to determine input rotation and torque, respectively. The regulator is interposed between the directional control valve and the engaged device. The regulator is controlled to maintain the servo hydraulic pressure at a predetermined value under the control of the electronic control unit until predetermined input rotation is detected and then to gradually raise the servo hydraulic pressure under the control of the electronic control on the basis of the value of input torque.

Abstract: An automatic transmission mechanism having multiple ratio gearing and clutch and brake elements operated by fluid pressure operated servos for changing speed ratio in the transmission and a controller for actuating and releasing the clutches and brakes in response to operating demands determined by sensed variables such as vehicle speed, engine torque, manual valve position, transmission turbine speed, and engine temperature, and means for achieving improved control of a synchronous downshift event by electronically regulating the exhaust pressure from an off-going friction element of the clutch and brake structure, thus controlling the torque-carrying capacity of that off-going element during the downshift interval.