A hybrid system includes a transmission control module, a power source, a transmission, and a drive train. The transmission control module partially operates the hybrid system and receives operating information from various components of the system, calculates power losses in the drive train, and calculates the driving torque needed to reach a target power profile determined from a driver's input.

This invention pertains to the field of power transmission. Machines using a power transmission mechanism for transmission of the mechanical power produced by a source (engine (2), electric motor, pneumatic and hydraulic pump) to another component of the machine (wheel (21), electric motor, electric generator, pneumatic and hydraulic pump) through multiple transmission paths (different gear ratios (14), (15)) are subjects of this invention. It is disclosed that control of a switching from one power transmission path to another is done in a manner involving simultaneous load transfer and speed synchronization rather than sequential performance of these two functions, and the resulting method developed in the invention leads to switching operations that produce less disturbance at the input of the said component. The said method is applied to the problem of controlling gearshifts in automatic transmissions of ground vehicles.

A method for operating a drive train of a motor vehicle, where the drive train includes a drive aggregate, a group transmission connected between the drive aggregate and a drive output, and a separating cutch connected between the drive aggregate and the group transmission. If a speed is lower than a limit value, the separating clutch is opened and for transmission preselection one or all the other sub-transmission(s) is/are changed to a friction-force-locking condition. The separating clutch is then at least partially closed and the drive aggregate is brought to a defined rotation speed. When a friction-force-locking group transmission is required, it is checked whether a starting gearshift or a driver-desired shift for the group transmission is called for and the target rotation speed of the drive aggregate is checked. Depending on the results, the sub-transmission can be synchronized by a transmission brake or by the drive aggregate.

A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining at least one of the throttle operator and throttle valve position, detecting a parking/drive away condition indicative of one of a parking operation and a drive-away operation of the vehicle, and, responsive to the detection, actuating the piston and controlling the piston force based on the at least one of the throttle operator position and the throttle valve position.

A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission is operatively connected to the engine and has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. At least one ground engaging member is operatively connected to the driven pulley and includes at least one of a wheel and a track. A piston is operatively connected to the driving pulley for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an engine speed, and controlling the piston force based on the engine speed.

Provided herein is a method and a control system for a multiple-mode continuously variable transmission having a ball planetary variator. The control system has a transmission control module configured to receive a plurality of electronic input signals, and to determine a mode of operation from a plurality of control ranges based at least in part on the plurality of electronic input signals. The transmission control module includes a CVP control module. In some embodiments, the transmission control module is configured to implement an off-road control process. The off-road control process receives a number of input signals indicative a driver's desired vehicle speed, and issues commands to adjust the variator to maintain the desired vehicle speed.

A method for operating a vehicle drive-train having a continuously power-branched transmission with secondary coupling. In the open operating condition of reversing clutches of a reversing gear unit, torque applied in the area of a drive output can be supported by a range group in the area of a variator. In the event of a command to interrupt the power flow between a drive engine and the drive output, it is checked whether the vehicle is on an inclined surface and if the result of that inquiry is positive, the power flow between the drive engine and the transmission is interrupted at the latest when the rotational speed of the drive output is reduced to zero by opening the reversing clutches, while the active connection between the drive output and the variator is maintained by way of the range group.

A method for operating an automatic transmission of a hybrid vehicle which has an electric traction machine and an internal combustion engine. A drag torque is provided at the electric traction machine. On the basis of a maximally available electric power for driving the electric traction machine, a characteristic map having respective curves for respective gears of the automatic transmission of the hybrid vehicle is created. The characteristic map is adjusted according to the drag torque to be provided by each curve being reduced by the drag torque to be provided. A shifting logic is specified in which respective shifting points for shifting the automatic transmission are defined at intersections of the curves of adjacent gears of the adjusted characteristic map, wherein the automatic transmission is shifted on the basis of the shifting logic in the respective shifting points.

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM controls a machine output of the machine by executing a transmission output control routine using transmission output parameters as feedback when transmission output parameter sensor signals are reliable. The ECM controls the machine output by executing a target engine speed control routine using an engine output speed sensor signals as feedback when the transmission output parameter sensor signals are nor reliable. In the target engine speed control routine, the ECM determines a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the target engine speed.

Disclosed are power machines, and drive systems for use thereon, as well as methods of controlling the displacement of a hydraulic drive motor. The drive system includes a drive pump capable of providing a hydraulic power output and a drive motor operably coupled to the drive pump that receives the hydraulic power output from the drive pump. The drive motor has an operating displacement that is variable between a minimum displacement and a maximum displacement and it provides a rotational output member. A shift actuator is operably coupled to the drive motor and it is configured to vary the displacement of the drive motor between the minimum displacement and the maximum displacement. A controller controls the shift actuator to cause the drive motor to provide infinitely variable displacement between the minimum and maximum displacements.