Abstract:
A control system is provided for a vehicle regulating engine speed during shifts so as to reduce driveline torque and shift shock. The control system includes separate microprocessor based engine and transmission controllers which communicate via a data link. When a shift is initiated, the transmission controller delays a first period of time CTSDELAY sufficient for the transmission to disengage the old gear ratio and then produces a CTSSPEED signal. The transmission controller continues to produce the CTSSPEED signal for a second period of time CTSDUR which corresponds to the time required for the transmission to engage the new gear ratio. The engine controller receives the desired engine speed signal and regulates engine speed into correspondence with the desired speed. During upshifts, the CTSSPEED signal is set to a speed which is a predetermined amount above the synchronization speed of the new gear for an upshift. Conversely, during downshifts, the CTSSPEED is set to a speed which is a predetermined amount below the synchronization speed in the new gear. The control system preferably includes a unit [means] for sensing a lockup time period corresponding to the time required for the transmission to lock up in the new gear ratio. The control system is capable of modifying the second time period CTSDUR as a function of the sensed lockup time period.
Abstract:
An adaptive control system/method for an at least partially automated vehicular mechanical transmission system (10) is provided for determining the value of a control parameter (T.sub.ACCES) indicative of accessory torque when the vehicle is in motion and the value of a control parameter (dES/dt rate) indicative of engine deceleration rate when the vehicle is not in motion. A relationship (dES/dt rate=A+B * T.sub.ACCES) between engine deceleration rate and accessory torque is determined and allows derivation of one parameter from the other parameter during vehicle operating conditions wherein the other parameter may be directly determined from sensed inputs (T.sub.EG, T.sub.BEF, ES).
Abstract translation:提供了一种用于至少部分自动化的车辆机械传动系统(10)的自适应控制系统/方法,用于确定当车辆运动时指示附件转矩的控制参数(TACCES)的值和控制参数 dES / dt率),表示车辆不运动时的发动机减速率。 确定发动机减速率与附件扭矩之间的关系(dES / dt速率= A + B * TACCES),并允许在车辆操作条件期间从另一参数导出一个参数,其中可以根据感测输入直接确定其他参数(TEG ,TBEF,ES)。
Abstract:
A controller for an automatic transmission which reduces wear of frictional engagement elements and shortens gear change time even when a gear change jump is made. The controller of the present invention includes a first hydraulic servo to which oil is supplied to make a gear change jump, a second hydraulic servo to which oil is supplied to make a gear change to an intermediate gear stage, a limited supply oil circuit having an oil flow limiting element, a quick supply oil circuit bypassing the oil flow limiting element and a pressure governor for regulating a line pressure to supply oil at a controlled pressure to the quick supply oil circuit. An oil path switching valve switches oil supply, to the first hydraulic servo or the second hydraulic servo, between the limited supply oil circuit and the quick supply oil circuit. Accordingly, when a gear change jump is made, oil is supplied to the first hydraulic servo via the quick supply oil circuit and the operating pressure can be increased quickly, so that the gear change time is shortened.
Abstract:
A control apparatus for a hydraulically operated vehicular transmission having a plurality of hydraulic engaging elements has an accumulator which is connected in parallel with a hydraulic engaging element for a low-speed transmission train and a back pressure generating source which generates a hydraulic oil pressure to be supplied to a back pressure chamber of the accumulator. The control apparatus includes a changeover valve which can be changed over between a first position in which the back pressure chamber of the accumulator and the back pressure generating source are brought into communication with each other and a second position in which the communication is cut off to lower a pressure in the back pressure chamber. The changeover valve is arranged to be changed over from the second position to the first position when a hydraulic oil pressure in the hydraulic engaging element for the low-speed transmission train has exceeded a predetermined pressure.
Abstract:
A shift control system of an automatic transmission includes a first element which is to be released in a shift operation, a second element which is to be engaged in the shift operation, and a target shift time set section for setting a target time period of the shift operation needed for releasing the first frictional element and engaging the second frictional element. A shift time calculation section is provided for obtaining an actual time period of the shift operation needed for releasing the first frictional element and engaging the second frictional element, and a releasing pressure control section is provided for receiving output of the target shift time set section and the shift time calculation section for controlling a releasing pressure of the first frictional element in the shift operation based on the difference between the target and actual time periods of the shift operation. An engaging pressure control section is used for controlling an engaging pressure of the second frictional element in the shift operation. A shift shock is effectively suppressed by the shift control system.
Abstract:
A shift control system for an automatic transmission including frictional engagement elements to be applied by actuating a piston by an oil pressure. The shift control system comprises: a pressure regulating valve for regulating the oil pressure to be fed to the frictional engagement elements and for controlling the regulated pressure level; a shift detector for detecting a shift to be executed by feeding the oil pressure to the frictional engagement elements; a low-pressure standby unit for setting the regulated pressure level of the pressure regulator valve to such a value during a predetermined time period after the shift has been detected that the oil pressure to be fed to the frictional engagement elements moves only the piston; and a booster for controlling the regulated pressure level so that the oil pressure to be fed to the frictional engagement elements may gradually increase after lapse of the predetermined time period.
Abstract:
In a control apparatus for a hydraulically operated vehicular transmission which has a plurality of hydraulic engaging elements, an orifice is disposed in an oil passage which is communicated with a hydraulic engaging element for a low-speed transmission train. The control apparatus has a bypass passage which bypasses the orifice, a control valve which can be switched between a communicated state in which the bypass passage is in communication and a cut-off state in which the communication of the bypass passage is cut off, and a control circuit which changes over the control valve to the communicated state under a predetermined condition at a time of switching from a running range to a neutral range.
Abstract:
A shift control system for an automatic power transmission is capable of optimizing operation timing of a timing valve and whereby eliminate a shift-shock and occurrence of racing. The system includes an input device including a detector for detecting a vehicle speed and a load detector for detecting an engine load, a switching device for switching states of the friction elements for establishing the transmission speed ratios, a switching controller for selecting a transmission speed ratio among the speed ratios on the basis of the inputs from the input device and issuing a shifting demand for the switching device, a measuring device for measuring an elapsed time from a timing of recognition of the shifting demand from the switching controller, a timing adjusting device for adjusting response of hydraulic pressure supply for the friction elements upon down-shifting, a weighting and summing derive for deriving weighted sum of inputs including at least the vehicle speed, the elapsed time from the timing of recognition of the shifting demand and the engine load, upon down-shifting, and a timing control device for outputting a control signal to operate the timing adjusting devicee to perform a predetermined operation when the weighted sum derived by the weighting and summing device exceeds a predetermined threshold value.
Abstract:
An automatic transmission control system has a plurality of frictional coupling elements within an automatic transmission which are selectively locked and unlocked in a particular way to place the automatic transmission into any desired gear in various ranges. Two specific frictional coupling elements, such as a low/reverse brake and a 3/4 clutch, may potentially cause mechanical locking of the automatic transmission when they are locked simultaneously. The automatic transmission control system, however, includes a first valve for connecting and disconnecting a supply of hydraulic pressure to the low/reverse frictional coupling element to lock and unlock the low/reverse frictional coupling element in low speed and reverse ranges, and a second valve for connecting and disconnecting a supply of hydraulic pressure to the 3/4 frictional coupling element to lock and unlock the 3/4 frictional coupling element. The first and second valves are disposed in series between a hydraulic pressure source and the low/reverse frictional coupling element and cooperate with each other so as to connect supply of hydraulic pressure alternatively to the low/reverse frictional coupling element and the specific frictional coupling element.
Abstract:
During downshift operation of an automotive automatic transmission in which a lower-speed clutch for establishing a lower-speed gear is engaged while higher-speed clutch, which has established a higher-speed gear, is disengaged, to increase the turbine rotational speed Nt toward a synchronous rotation speed Ntj associated with the lower-speed gear, speed change control is carried out according to the same control method regardless of whether the engine is in a power-on or power-off state. A target change rate (Nir)' of turbine rotational speed associated with the higher-speed clutch and a target change rate (Nia)' of turbine rotational speed associated with the lower-speed clutch are set, and a change rate (Nia)' of the turbine rotational speed is detected. The transmission torque through the higher-speed clutch is controlled in a feedback manner such that the detected change rate (Nt)' coincides with the change rate (Nir)'. Further the transmission torque through the lower-speed clutch is feedback-controlled such that the change rate (Nt)' coincides with the change rate (Nia)', thereby carrying out downshift.