Abstract: A shift control system comprises a diameter-change calculation which calculates the difference between the diameters of the contact circles at present and after a shift to a target speed change ratio and a slip prevention thrust calculation which calculates a slip prevention thrust necessary for transmitting the power through a V belt without slip between the V belt and the drive and driven pulleys. A speed ratio maintaining thrust calculation which calculates a speed ratio maintaining thrust that is an addition to the slip prevention thrust for maintaining the current speed change ratio in constant condition and for transmitting the power without any slip of the belt and a additional thrust calculation which calculates a shifting additional thrust that is added for a contact-circle enlarging pulley to achieve a shift to the target speed change ratio.

Abstract: A control system for a continuously variable automatic transmission for an automotive vehicle, includes a throttle opening sensor that detects a throttle opening, and a controller that executes a change-speed control in a normal mode in which a desired transmission input speed is determined based on operating conditions of the vehicle and a desired transmission ratio is determined based on the desired transmission input speed when the throttle opening is less than a first value, and that executes the change-speed control in a linear mode in which the desired transmission ratio is fixed to a second value when the throttle opening is greater than or equal to the first value. The second value is set based on the desired transmission ratio used in the normal mode prior to switching to the linear mode.

Abstract: The invention relates to a method and device for a coupling (2) in a motor vehicle transmission, the coupling being controlled and regulated during two operational states by way of a first regulating circuit (3). The regulated quantity corresponds to the actual value of a differential engine speed of the coupling (2). The first state corresponds to a starting action and the second state to operation with a variable transmission ratio.

Abstract: A CVT control method includes the steps of calculating a target speed ratio of a CVT between maximum and minimum values of a plurality of speed ratios preset corresponding to a plurality of engine operation modes, and controlling the CVT according to the target speed ratio.

Abstract: A method and apparatus for operating an automatic transmission as a function of the engine rotational speed of a variable speed internal combustion engine. Upon a failure of the electronic control system, a return home of a motor vehicle under its own power is enabled. A delivery system delivers a working medium with which a transmission ratio adjusting device is actuated by a first control device that, in turn, is controlled by a pilot pressure that can be accurately changed by a second control device to actuate the transmission ratio adjusting device. The pilot pressure for controlling the first control device is changed by a third control device as a function of the rotational speed of the internal combustion engine when an adjusting device is switched out of a normal operation position into an emergency operation position.

Abstract: A forward-speed/reverse-speed changeover mechanism 6, serving as a motive-force connection/disconnection mechanism, is accommodated into a housing member 8 fixed to a casing 1. To the forward-speed/reverse-speed changeover mechanism 6 an input end of a primary shaft 3 is connected. The housing member 8 rotatably supports the primary shaft 3 via a bearing member 11. On an imaginary line intersecting the primary shaft 3 perpendicularly and passing through the bearing member 11, a load-receiving element 1b, 8b is provided between the housing member 8 and the casing 1. The tension of a belt 17 is received by the load-receiving element 1b, 8b. As a result, it is possible to provide a bearing structure of a continuously variable transmission enabling holding the bearing members of the primary and secondary shafts at their regular positions against the tension of the belt and maintaining an optimum belt-alignment, thereby enhancing the durability of the continuously variable transmission.

Abstract: A method of diminishing shift shock in a stepped shift mode in a continuously variable transmission. A continuously variable transmission having an automatic shift mode and a stepped shift mode possesses a shift shock diminishing control function. In this control, when shift-down is made in the stepped shift mode (S.1), a timer is allowed to start counting (S.2) and the magnitude of deceleration G during change of the change gear ratio by a control motor is compared with a threshold value (S.4), and if the deceleration magnitude is larger than the threshold value, the supply of electric power to the control motor is stopped for only a very short time to decrease the deceleration G thereby diminishing the shift shock (S.5).

Abstract: A speed change control system for a continuously variable transmission, for controlling a gear ratio by deciding an abrupt acceleration demand of a driver, to effect an abrupt speed change when it is decided that the driver demands an abrupt acceleration. The speed change control system comprises: a drive state decider for deciding that the vehicle has changed from a driven state to a drive state, when said abrupt acceleration is demanded at the driven state; and a speed change controller for controlling said continuously variable transmission to effect said abrupt speed change, after said drive state decider decides that the vehicle has changed from the driven state to the drive state.

Abstract: An apparatus for controlling a continuously variable transmission is disclosed. The apparatus includes (i) an input shaft driven by an engine, (ii) an output shaft, (iii) an operator input for generating speed commands, and (iv) a controller operable to receive said speed commands and generate transmission ratio commands which control a ratio of a speed of the output shaft to a speed of the input shaft. An upper transmission ratio limit is defined by first engine speed and a lower transmission ratio limit is defined by a second engine speed. When the speed command requires a transmission ratio command greater than the upper transmission ratio limit, the controller adjusts the transmission ratio command to the upper transmission ratio limit, whereas when the speed command requires a transmission ratio command less than the lower transmission ratio limit the controller adjusts the transmission ratio command to the lower transmission ratio limit.

Abstract: A control unit of a continuously variable transmission computes a speed ratio command value based on a final target ratio, a time constant representing a predetermined dynamic characteristic and a time constant representing an estimated dynamic characteristic of the transmission so that a real speed ratio approaches the final target ratio according to a running state under the predetermined dynamic characteristic. A transient target ratio is computed based on the final target ratio and time constant representing the predetermined dynamic characteristic, a correction amount of the speed ratio command value is computed based on the difference between the transient target ratio and real speed ratio, and the transmission is controlled based on the speed ratio command value after correction by this correction amount.

Abstract: The invention proceeds from a control of a transmission which is adjustable continuously with respect to its transmission ratio, for a motor vehicle. The transmission together with a drive unit is mounted in the drive train of the motor vehicle and the drive unit has an adjustable drive torque. The transmission includes a drive end as well as an output end and operative means for establishing a mechanical operative connection between the drive end and the output end. Furthermore, detection means for detecting a slip quantity is provided. The slip quantity represents the slip between the operating means and the drive end and/or output end. Pregivable measures are initiated in response to a pregiven value of the slip quantity. The essence of the invention is that measures as follows are initiated: a drive of a clutch mounted in the drive train; and/or, a change of the transmission ratio; and/or, a change of the output torque of the drive unit.

Abstract: When a slip control system starts operating, a vehicle speed VSP used for speed change control is simultaneously changed over from a sensor detected vehicle speed VSPSEN to an estimated vehicle speed VSPFL. On the other hand, when the slip control system has stopped, it is first determined whether a speed ratio variation amount, due to the change-over of the vehicle speed used for speed change control from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN, is less than a permissible amount. When it is determined that the speed ratio variation amount is smaller than the permissible amount, the vehicle speed used for speed change control is changed over from the estimated vehicle speed VSPFL to the sensor detected vehicle speed VSPSEN. By performing this change-over, a sharp variation of the vehicle speed used for speed change control is suppressed, and a sharp variation of the speed ratio leading to shocks or slipping is suppressed.

Abstract: In a torque converter(T/C) speed ratio calculation section, the speed ratio in a torque converter is determined from the revolution speed of the engine and the revolution speed of the primary pulley. A T/C torque ratio calculation section then calculates the torque ratio from the speed ratio. An input torque estimation section then estimates the input torque input into a continuously variable transmission from the above torque ratio and the engine output torque determined by an engine torque calculation section. The T/C speed ratio calculation Section is provided with a correction amount calculation section and correction is performed such that the speed ratio when the accelerator pedal is depressed is reduced in the direction in which it is less than Np/Ne.

Abstract: A method for control of internal combustion engine powered vehicles wherein the vehicle driver, during normal vehicle operation, determines the vehicle velocity essential by controlling the gear transmission ratio between vehicle's engine and it's wheels. Thereby the rotational speed of the engine is kept low resulting in high engine energy efficiency during normal operation, while the driver by reflex, immediately and without auxiliary controls is able to shift to high engine speeds and corresponding high engine power.

Abstract: A motor vehicle has a continuously variable transmission and a hydraulic device to perform the functions of changing as well as maintaining the ratio of the continuously variable transmission. The hydraulic device comprises a valve arrangement with at least one connector terminal for controlling a transmission ratio change and at least one connector terminal for maintaining the transmission ratio at a set level.

Abstract: The invention relates to a method for manual control of the ratio of a continuously variable transmission (CVT) for a vehicle. The CVT has one control device, one shifting or selector device, one starting element and one variator for ratio adjustment and is driven by an internal combustion engine. The control device processes input signals derived from a driver-vehicle system within the scope of an operating strategy under the control of the reduction ratio, the rotational speed of the prime mover, or an input rotational speed of the variator. The operation strategy automatically selects in an automatic operating mode the transmission ratio. In a manual operating mode, the driver can engage directly in the selection of the transmission ratio via the shift or selector device. It is proposed that in the operating mode there is manually preset a signal proportional to the vehicle speed which is further processed as a theoretical guidance for the operating point of the engine-transmission unit.

Abstract: An apparatus and method of operating an adaptive drive system of a motor vehicle which reduces drive line wear, improves safety margins and permits weight reduction in drive line components activates a clutch between a primary and secondary drive line when the vehicle is determined to be heavily loaded. The method steps include sensing the position of a throttle position sensor, sensing the instantaneous speed of a motor vehicle and computing instantaneous acceleration, determining whether the ratio of vehicle acceleration to throttle position is less than predetermined threshold value and engaging a transfer case clutch to transfer drive torque from a primary drive line to a secondary drive line. Operation of this method is transparent to the driver inasmuch as the clutch is activated when the vehicle is heavily loaded as determined by the throttle position to acceleration ratio.

Abstract: When a slip control system is not operating, a speed ratio control device uses a sensor detected vehicle speed for speed ratio control, and when the slip control system is operating, it uses an estimated vehicle speed for speed ratio control. It is determined whether a variation amount of the estimated vehicle speed is greater than a threshold set to a variation amount which could not be obtained when there is no error. When the variation amount of the estimated vehicle speed is greater than the threshold, it is determined that the estimated vehicle speed is abnormal, and use of the estimated vehicle speed for speed ratio control is prohibited.

Abstract: The improved CVT control apparatus for a vehicle is disclosed. By using the CVT control apparatus, it becomes possible that the drive feeling is constant independently of a running state, the vehicle is accelerated as the driver's intention if accelerated due to the actuation of an accelerator pedal, and the run of the vehicle is performed so as to improve the fuel consumption rate if the acceleration is not required.

Abstract: In a hybrid vehicle wherein the rotation torques of a motor and engine are input to a continuously variable transmission, a drive force is controlled by a microprocessor programmed to set a target drive power (tPO) based on a depression amount of an accelerator pedal (APO) and a vehicle speed (VSP), set a battery power (PB) based on a battery charge amount (SOC), set a target engine power (tPE) based on the target drive power (tPO) and the battery power (PB). The microprocessor is also programmed to set a limited target engine power (tPELMT) to zero when the target engine power (tPE) is less than a predetermined value, and set the limited target engine power (tPELMT) equal to the target engine power (tPE) when the target engine power (tPE) is larger than the predetermined value.

Abstract: A method for influencing a shift process connected with a change in transmission ratio when driving a motor vehicle that has a set of driven wheels subject to longitudinal and transverse forces, the method including detecting whether or not the vehicle is traveling around a curve and, if doing so when the shift process is in progress, influencing the shift process so as to decrease the longitudinal forces that act on the driven wheels as a result of the shift process. Also disclosed is an apparatus for performing the disclosed method including a detector for detecting whether or not the vehicle is traveling around a curve and a transmission ratio shifter responsive to the detector that, if the vehicle is traveling around a curve when the shift process is in progress, performs the shift process so as to decrease the longitudinal forces that act on the driven wheels as a result of the shift process.

Abstract: In a control system for controlling a continuously variable transmission of a vehicle having an idle speed control valve disposed in a bypass passage around a throttle valve, a throttle opening angle guard value is set to specify a throttle full-closed change gear line in accordance with engine coolant temperature. The actual throttle opening angle is compared with the throttle opening angle guard value, and the larger of them is set as a change gear ratio calculating throttle opening angle. Further, by referring to a basic change gear characteristic map, and in accordance with the change gear ratio calculating throttle opening angle and vehicle speed as parameters, a target primary pulley revolution number is set.

Abstract: In an infinite speed ratio transmission comprising a continuously variable transmission (2), reduction gear unit (3) and planetary gear set (5), the speed ratio of the continuously variable transmission (2) is controlled by a step motor (36). A range selected by a selector lever (86) is detected by a sensor (84). When the selected range has changed from a stationary range to one of a forward motion range and a reverse motion range, a microprocessor (80) first drives the step motor (36) to a predetermined position (S48, S54).

Abstract: Hydraulic pressure generated by an oil pump driven by an engine is regulated to a secondary pressure by means of a secondary pressure control valve. The secondary pressure is employed for controlling a secondary pulley and a primary pulley. On the other hand, the secondary pressure is reduced to a clutch pressure by means of a clutch pressure control valve. The communication between an apply chamber and a release chamber of a torque converter, oil chambers of actuators for a forward clutch and a reverse brake of a forward and reverse changeover apparatus and a clutch pressure line and a lubrication pressure line are controlled by means a switching valve. The clutch pressure is regulated to a high clutch pressure and to a low clutch pressure, respectively by controlling reverse signal pressures supplied to these outer pilot chambers.

Abstract: A transmission mechanism of continuously variable transmission in a vehicle comprises a primary pulley and a secondary pulley provided with a first cylinder chamber and a second cylinder chamber, with groove widths being changed by supply of hydraulic pressure, and a belt provided between the pulleys. A hydraulic pressure to the first cylinder chamber is controlled by CVT control unit through a shift control valve according to a driving state of the vehicle, and the second cylinder chamber is continuously supplied with a line pressure. CVT control unit includes an internal memory to retain a heavy-current system fail flag according to the failure information inputted from a motor control unit.

Abstract: A working oil filter device for a continuously variable transmission including a primary pulley and a secondary pulley, between which a belt is made to run. The filter device comprises: a secondary pressure adjust valve for adjusting the pulley groove width thereof; a clutch pressure adjust valve for adjusting the clutch pressure; and a filter for filtering the working oil. The device can comprise a primary pressure adjust valve is provided, in place of the clutch pressure adjust valve. Further, The device can comprise a lubrication pressure adjust valve and a bypass oil passage for returning a drain oil.

Abstract: A transmission includes a transmission input speed sensor which generates transmission input speed signals indicative of an input speed to the transmission and a transmission output speed sensor which generates transmission output speed signals indicative of an output speed of the transmission. The transmission further includes a controller operable to receive the transmission input speed signal and the transmission output speed signal and determine a transmission ratio based on the transmission input speed signal and the transmission output speed signal. The controller is further operable to calculate a rate of change of the transmission ratio and initiate a transmission range shift based on the transmission ratio, the rate, and a shift completion ratio such that the transmission range shift is completed when the transmission is at the predetermined shift completion ratio.

Abstract: The invention proceeds from a control of a transmission which is adjustable continuously with respect to its transmission ratio, for a motor vehicle. The transmission together with a drive unit is mounted in the drive train of the motor vehicle and the drive unit has an adjustable drive torque. The transmission includes a drive end as well as an output end and operative means for establishing a mechanical operative connection between the drive end and the output end. Furthermore, detection means for detecting a slip quantity is provided. The slip quantity represents the slip between the operating means and the drive end and/or output end. Pregivable measures are initiated in response to a pregiven value of the slip quantity. The essence of the invention is that measures as follows are initiated: a drive of a clutch mounted in the drive train; and/or, a change of the transmission ratio; and/or, a change of the output torque of the drive unit.

Abstract: A driving force control system for an automotive vehicle using driving torque produced by at least one of an internal combustion engine and an electric motor for propulsion, and including a battery and a power-transmission mechanism having a continuously variable transmission, comprises sensors detecting vehicle speed, engine speed, an accelerator operating amount, a state of charge of the battery.

Abstract: A process for evaluation of cornering of a vehicle equipped with an automatic transmission by use of electronic transmission control device having a calculation unit, a micro-controller, a memory device and a control device for start up of a hydraulic transmission control device. During a first processing operation (S1), a transverse acceleration (a_Quer) of the vehicle is determined by the calculation unit (30) from wheel speed (n_Rad) of the vehicle measured by a measuring device (34). During a second processing operation (S2), a driver-type theoretical value (FT_Soll) is determined from a vehicle transverse acceleration (a_Quer) and a vehicle speed (v_F). A gear change characteristic line (SL) is determined, based upon an increment (INKR) between the driver-type theoretical value (FT_Soll) and a driver-type actual value (FT_Ist), from several gear change characteristic lines each one associated with a certain driver type or cornering style.

Abstract: A shift control apparatus of a continuously variable transmission for a vehicle comprises sensors for detecting operating conditions of the transmission and a motor connected to the transmission. A controller of the shift control apparatus stores different shift maps and employs one of them according to a driver's command or vehicle driving condition. The controller decides a target value of an input rotation speed of the transmission from an output rotation speed of the transmission and the load condition of a motor on the basis of the shift map and continuously changes a gear ratio of the transmission so that the transmission input rotation speed is adjusted to the target value. The controller can change the rate of the shift speed indicative of a time period of a gear ratio changing operation according to a driver's command.

Abstract: In a vehicle transmission wherein plural speed change ratios from a largest speed change ratio to a smallest speed change ratio are selectively applied according to a command input by a driver, a real speed change ratio of the transmission is detected. It is determined whether or not the transmission is performing a shift-down based on the input command and the real speed change ratio. A shift-down limit speed change ratio is determined based on the speed change ratio before the shift-down operation is performed, and when the engine brake of the vehicle is operating, the transmission is controlled so as not to apply a speed change ratio larger than this shift-down limit speed change ratio. Due to this, the driver does not experience an excessive engine braking sensation even when an extreme speed change command is issued.

Abstract: A speed change ratio of a stepless transmission of a vehicle is controlled so as to decrease the greater the vehicle speed, but this control of speed change ratio is suppressed when the drive wheels are slipping. This prevents misinterpretation of the slipping of the drive wheels as an increase of vehicle speed, and prevents shift-up of the transmission when the drive wheels are slipping.

Abstract: A slip of drive wheels of a vehicle driven via a continuously variable transmission is suppressed due to fuel cut of a multi-cylinder engine. The speed change response characteristics of the transmission are made to vary according to the engine rotation speed when fuel cut is performed. A speed change ratio command value is calculated from a target speed change ratio based on a first-order delay due to a predetermined time-constant. The response of the transmission is thus delayed for low engine rotation speed than for high rotation speed, and undesirable fluctuation of the speed change ratio when the drive wheels slip is prevented.

Abstract: A transmission control system of an automotive vehicle with a continuously variable automatic transmission, comprises an electronic transmission control unit which detects an acceleration of a drive wheel of the vehicle, and compares the acceleration of the drive wheel to a predetermined acceleration value. The control unit operates to inhibit only the upshifting action by preventing a speed ratio of the continuously variable automatic transmission from being upshifted toward a speed ratio less than a predetermined upshift limiting threshold.

Abstract: In a toroidal continuously variable transmission for a vehicle, either of an automatic operation mode and a manual operation mode is selected by a driver via a selector lever (59). A speed ratio grade in the manual operation mode is also designated via the selector lever (59) by the driver. A controller (61) is programmed to control a speed ratio of the transmission to a target speed ratio corresponding to the designated speed ratio grade. The controller (61) is further programmed to prevent the speed ratio from varying after an input torque to the transmission has changed. This control may be realized by setting different target speed ratios for an identical speed ratio grade according to the input torque of the transmission.

Abstract: A first final target input rotation speed is calculated according to a throttle opening and a vehicle speed, and a second final target input rotation speed is calculated by applying an upper limit to the first final target input rotation speed. The upper limit is determined so as to reduce noise outside the vehicle. A second final target speed ratio is set from the vehicle speed and second final target input rotation speed, and a time constant of a speed ratio variation is determined from the vehicle speed and first final target input rotation speed. By transiently controlling the speed ratio variation using the second final target speed ratio and time constant thus obtained, an excessive increase of engine rotation speed is prevented while retaining a desirable feeling of acceleration when there is a kickdown operation of the vehicle.

Abstract: A method for controlling a vehicle drive unit, which comprises a drive engine and a transmission with a continuously variable gear ratio, comprises the following steps: a) the required vehicle acceleration (ASOLL) is calculated from a throttle control lever position (XFP, XHG) and the current speed of travel (VFZ), b) a required transmission variation (IGDSOLL1) is calculated from the required vehicle acceleration (ASOLL) and the current rotation speed (NMOT) of the drive engine, c) a limited required transmission variation (IGDSOLL) is determined from the required transmission variation (IGDSOLL1) such that the engine rotation speed (NMOT) does not fall below a value which depends on the position of the power control element (XEP) of the drive engine, d) the continuously variable transmission is varied in accordance with (IGDSOLL); e) the actuation parameter (XEPSOLL) for the power control element of the drive engine is obtained directly from the throttle control lever position (XFP, XHG).

Abstract: A controller (61) calculates a transient target speed ratio based on a final speed ratio set according to a vehicle running condition and second order delay time constant gains (75, S99), and control a speed ratio of a continuously variable transmission to the transient target speed ratio via an actuator (4) (87, S103). The controller (61) also calculates the deviation between the final target speed ratio and transient target speed ratio (74, S95), and determines the second order delay time constant gains based on the deviation (74, S98). Preferably, the gains are determined so that the response rate is slower the larger the deviation (74, S134, S135, S136, S137, S139, S140, S141).

Abstract: A system for controlling motive force of a vehicle having an engine and an automatic transmission connected to the engine to transmit engine torque to a drive shaft of the vehicle, wherein a control mode is selected from among a plurality of predetermined control modes in response to a calculated desired motive force and vehicle speed such that the fuel economy is enhanced and engine torque and speed (gear) ratio are controlled in response thereto. Moreover, the desired motive force is calculated by obtaining a difference between the wide-open-throttle motive force and the full-closed-throttle motive force and by multiplying the difference by a calculated ratio of motive force. Furthermore, the calculated desired output of the engine and the desired gear ratio are controlled such that the desired motive force is generated when the desired motive force is discriminated to be achievable.

Abstract: A method is provided for controlling an automatic transmission. The method initially determines if a kick down gear change is required. If so, the method determines if the throttle rate is increasing. If the throttle rate is increasing, the method determines if the throttle rate is less than a pre-selected threshold. If the throttle rate is greater than or equal to the pre-selected threshold, the kick down gear change is performed at an aggressive rate. However, if the throttle rate is less than the pre-selected threshold, the kick down gear change is performed at a slower rate.

Abstract: A control for a continuously variable unit (CVU) provides control pressures to the variable sheave portions of the CVU pulleys. A first of the pulleys has a direct control pressure and the second of the pulleys has a control pressure proportional to the direct control pressure. The proportional pressure is established by a pair of control valves. One of the control valves issues a bias pressure, proportional to the commanded ratio in the CVU, to the other of the control valves. The other control valve communicates a sheave control pressure, proportional to or equal to the bias pressure, to the second pulley to control the relative position of the variable sheave.

Abstract: A basic speed change ratio of a continuously variable transmission is set depending on operation conditions, a target speed change ratio that follows the basic speed change ratio at a predetermined rate of changing the speed is obtained, and the speed change ratio is controlled according to the target speed change ratio. Based on the basic speed change ratio and the target speed change ratio, furthermore, a rate of progress in the change of speed is operated according to rate of progress=1--(.vertline.basic speed change ratio--target speed change ratio.vertline.)/basic speed change ratio. Based on the rate of progress and the throttle opening degree, the up-shift is discriminated to be in any one of a first up-shift mode where the throttle opening degree is maintained constant, a second up-shift mode where the throttle is fully closed or a third up-shift mode where the throttle is closed to a half opened state to shift the acceleration to a steadily traveling state.

Abstract: In a hybrid vehicle wherein the rotation torque of a motor and engine are input to a continuously variable transmission, a target speed ratio is determined from a target engine rotation speed set based on a target drive torque of said vehicle and a vehicle speed. A target combined torque of the motor and engine is set based on the target drive torque and a real speed ratio of the transmission. A target motor torque is determined based on the target combined torque and the input rotation speed of the continuously variable transmission. A value obtained by subtracting the target motor torque from the target combined torque is set equal to a target engine torque. The drive force of the hybrid vehicle is optimized by controlling the engine, motor and continuously variable transmission by the target engine torque, target motor torque and target speed ratio thus obtained.

Abstract: The invention relates to a method for controlling a continuously variable transmission with an electrohydraulic control, a selector device, and a controllable engaging clutch of a motor vehicle, especially one powered by an internal combustion engine, with a control device in a first operating mode automatically selecting and adjusting a gear ratio for the transmission from signals of the selector device and the operating parameters of the motor vehicle such as the throttle angle, driving speed and engine rpm, by means of curves selectable by the driver.It is proposed, in a second operating mode, to simulate a multi-step transmission influenceable directly by the driver. In order to permit use of this operating mode, only a few preset gear ratios are made available to the driver.

Abstract: According to a torque converter lockup control, a lockup actuator, including a lockup solenoid, is operative responsive to an output command signal issued by a controller to adjust lockup clutch engagement force to a commanded value. The lockup clutch engagement force is a force with which the lockup clutch is engaged. The controller determines the commanded value as a function of a deviation between a current value of slip speed within the torque converter and a desired value thereof. For preventing the lockup clutch from shifting deeply into its converter position when the deviation persists to stay in the neighborhood of zero, the controller sets a limit to the determined commanded value during operation of the lockup clutch in the slip lockup mode.

Abstract: An electronic transmission control system having a fail-safe system for an automotive vehicle with a continuously variable automatic transmission whose speed-change ratio is changeable continuously depending on vehicle speed and engine load, comprises a hydraulic modulator producing at least a regulated line pressure necessary to adjust the speed-change ratio hydraulically, a desired speed-change ratio arithmetic processing section for calculating a desired speed-change ratio based on the vehicle speed and the engine load, and a desired line pressure arithmetic processing section for calculating a desired line pressure based on the desired speed-change ratio and the engine load.

Abstract: A drive device for an engine-driven load, which in the drive direction successively includes an engine, a torque converter with an input shaft and an output shaft, and a continuously variable transmission unit with a primary shaft and a secondary shaft, between which torque can be transmitted with the aid of friction forces. The nominal torque which can be generated by the combination of engine and torque converter on the primary shaft of the transmission unit is greater than the maximum slipping torque of the transmission unit. The device is provided with devices which act on parts of the drive device in such a manner that the torque which can actually be generated in operation by the combination of engine and torque converter on the primary shaft of the transmission unit is limited. The limited level for the torque is controlled in such a manner that the torque generated is at most equal to the maximum slipping torque of the transmission unit.

Abstract: A shift control apparatus outputs a command transmission ratio to a continuously variable transmission (CVT) to control a real transmission ratio of the CVT. The shift control apparatus comprises a shift mode determining section determines whether an actually selected shift mode is an automatic upshift or a power-down upshift (foot-release upshift), on the basis of the result of a previously selected shift mode, a difference between a final objective transmission ratio and a transient objective transmission ratio and a rate of change in the transmission ratio per time. The dynamic characteristic selecting section determines the dynamic characteristic according to the determined shift mode.

Abstract: For a CVT it is proposed to determine an operating point from the number of revolutions of the primary disc (12) and the number of revolutions of the secondary disc (13). The operating point is assigned to a first characteristic field which has ranges of unauthorized ratios and one range of authorized ratio. If an error occurs, the pressure level in the adjustment area of the secondary disc (pSEK) is increased in a first step. If the error continues an emergency program is activated in a second step.