摘要:
Disclosed is a shift control method for automatic transmissions. The shift control method includes the steps of determining if all conditions for performing closed-throttle upshifting are met after information of whether a vehicle is in a driving state is read; establishing an initial duty value, first and second ramps for performing duty control, and duty signal output times, all from a closed-throttle upshifting map data, and determining a duty compensating value from a hydraulic pressure compensating map table; adding the initial duty value and duty compensating value to calculate an initial duty control value, and outputting the initial duty control value as ramps to perform shifting; subtracting engine RPM from turbine RPM and determining whether the resulting value is equal to or less than a predetermined critical value in a state where shifting is being performed using the initial duty control value; adding a predetermined compensating duty value to the initial duty control value to increase duty control, then performing duty control to the determined ramps and shifting to a target shift range; determining if the conditions for open-throttle upshifting are met; determining if upshifting is completed; determining if a final duty control hold time has exceeded a critical hold time; and setting the duty value to "0" to maintain the present state of reacting and friction elements.
摘要:
Shift shocks by controlling the hydraulic pressure on the hydraulic servos of the friction engagement elements. A control apparatus calculates a target hydraulic pressure P TA for a condition at the start of the inertia phase in accordance with the input torque, and calculates a gradient based on the target hydraulic pressure and a predetermined time t TA , and performs the first up-sweep of hydraulic pressure with the gradient. Then, a relatively gradual gradient δP TA is set based on a target rotation change rate for the input rotational speed to provide a predetermined change amount when the hydraulic pressure becomes the target hydraulic pressure P TA . The control apparatus performs the second up-sweep with the gradient δP TA . When the rotational speed change ΔN of the input rotation becomes a rotation change start determining rotational speed dN S that is detectable by an input shaft rotational speed sensor, the control apparatus feedback-controls the hydraulic pressure with a predetermined gradient while referring to the input rotation change. Further, the control apparatus detects the target shift start time and the rotational speed change rate at the target shift start time to learn and correct the target hydraulic pressure P TA , the gradient δP TA of the second sweep section, and the target shift start time t aim .
摘要:
A self-organising fuzzy logic controller develops an adaptive pressure adder that modifies the magnitude of pressure supplied to a friction element of an automatic transmission. The controller uses a turbine speed versus engine torque table in KAM (Keep Alive Memory) to store the adaptive pressure adder for each shift. Tables in KAM represent fuzzy rules which are altered based on shift performance criteria to produce a self-organising fuzzy logic controller. The criteria, which define shift performance, include the ratio change slip time and the initial ratio change time divided by the desired slip time (called target ratio). The desired slip time is determined from a calibratable matrix. After a shifting event, an adaptive pressure adjustment is determined for the next shifting event having the same conditions. A two-input (slip time and target ratio) fuzzy logic controller is used to determine the pressure adjustment. The adaptive pressure adjustment from the fuzzy controller is then increased if stage time is greater than a calibratable value. The adaptive pressure is also multiplied by a factor determined from the deviation in the throttle position reading for the shift event. Once the adaptive pressure is calculated, the adjustment is added to the cells of the adaptive pressure matrix that correspond to the turbine speed and engine torque conditions.
摘要:
A transmission control system for a vehicle having an engine with an output shaft, a torque converter, a stepped automatic transmission mechanism, and a clutch for engaging and releasing a plurality of gear shafts and input/output shafts with each other so as to change a shift change ratio by operation of the clutch. The control system produces a shift signal output indicating a shift change ratio of the stepped automatic transmission mechanism, detects an input torque of the stepped automatic transmission, recognizes an actual mechanical shift start timing of the stepped automatic transmission mechanism and changes engaging pressure on the clutch in accordance with a manipulation variable. An input torque-manipulation variable relationship between the input torque and the manipulation variable for every shift change ratio indicated by every shift signal and every mode of shift change ratios is stored. A manipulation variable calculation is performed when the shift signal and the shift signal output changes and the actual mechanical shift start timing is recognized.
摘要:
Uncomfortable travel of a vehicle due to engine brake actions during the travel of the vehicle in traffic is prevented without using an one-way clutch within a transmission mechanism. An automatic transmission is composed of rotational elements that are braked at the time of establishing low stages, a brake B-3, 32 that brakes the rotational elements, and control systems 5, 6 which control the oil pressure of the hydraulic servo 4 in the brake. A band brake B-3 that creates differences in application forces, using self-energizing and deenergizing actions, serves as the brake, which is set to have an area in which the oil pressure during the drive is lower than the oil pressure during the non-drive, by setting the self-energizing direction as a direction of rotation of the rotational element 31 during the drive and the deenergizing direction as an opposite direction of rotation of the rotational element during the non-drive. The control systems have a supplying mechanism which supplies oil to the hydraulic servo of the band brake at an oil pressure P MD that is lower than the oil pressure P EB during the non-drive and is equal to or higher than the oil pressure P FR during the drive.
摘要:
The present invention has been made to execute speed change control appropriately under any traveling condition during an up-shift control in speed change by change-over, without increasing the number of control logic. Engagement side hydraulic pressure sweeps up as a result of arithmetic operation by torque phase speed change control. Disengagement side hydraulic pressure is calculated by initial speed change control, dependent on the engagement side hydraulic pressure. The engagement side hydraulic pressure acts primarily and the disengagement side hydraulic pressure carries out follow-up control. Consequently, the same control can be executed regardless of power-on state or power-off state and regardless of a vehicle traveling condition. Accordingly, speed change control can be always executed on the same control stage.
摘要:
A transmission control system for a vehicle having an engine with an output shaft, a torque converter, a stepped automatic transmission mechanism, and a clutch for engaging and releasing a plurality of gear shafts and input/output shafts with each other so as to change a shift change ratio by operation of the clutch. The control system produces a shift signal output indicating a shift change ratio of the stepped automatic transmission mechanism, detects an input torque of the stepped automatic transmission, recognizes an actual mechanical shift start timing of the stepped automatic transmission mechanism and changes engaging pressure on the clutch in accordance with a manipulation variable. An input torque-manipulation variable relationship between the input torque and the manipulation variable for every shift change ratio indicated by every shift signal and every mode of shift change ratios is stored. A manipulation variable calculation is performed when the shift signal and the shift signal output changes and the actual mechanical shift start timing is recognized.
摘要:
A transmission control system for a vehicle having an engine with an output shaft, a torque converter, a stepped automatic transmission mechanism, and a clutch for engaging and releasing a plurality of gear shafts and input/output shafts with each other so as to change a shift change ratio by operation of the clutch. The control system produces a shift signal output indicating a shift change ratio of the stepped automatic transmission mechanism, detects an input torque of the stepped automatic transmission, recognizes an actual mechanical shift start timing of the stepped automatic transmission mechanism and changes engaging pressure on the clutch in accordance with a manipulation variable. An input torque-manipulation variable relationship between the input torque and the manipulation variable for every shift change ratio indicated by every shift signal and every mode of shift change ratios is stored. A manipulation variable calculation is performed when the shift signal and the shift signal output changes and the actual mechanical shift start timing is recognized.
摘要:
An automatic transmission control apparatus has a clutch (1), a hydraulic servo for the clutch, a fluid pressure control unit, a range shift detector, and an electronic control unit. The fluid pressure control unit has a manual valve, a pressure regulating valve device, and a changeover valve device. The electronic control unit controls the changeover valve device and the pressure regulating valve device. Immediately after shift to the forward driving range, the electronic control unit holds the changeover valve device in such a state that a forward driving range pressure is supplied without passing through the pressure regulating valve device. Then, the electronic control unit shifts the changeover valve device to such a state that a regulated pressure is supplied from the pressure regulating valve device, which has been switched to a pressure regulating state by the electronic control unit. This control operation precisely sets the fluid pressure changeover timing and the initial fluid pressure.
摘要:
An automatic transmission control apparatus has a clutch (1), a hydraulic servo for the clutch, a fluid pressure control unit, a range shift detector, and an electronic control unit. The fluid pressure control unit has a manual valve, a pressure regulating valve device, and a changeover valve device. The electronic control unit controls the changeover valve device and the pressure regulating valve device. Immediately after shift to the forward driving range, the electronic control unit holds the changeover valve device in such a state that a forward driving range pressure is supplied without passing through the pressure regulating valve device. Then, the electronic control unit shifts the changeover valve device to such a state that a regulated pressure is supplied from the pressure regulating valve device, which has been switched to a pressure regulating state by the electronic control unit. This control operation precisely sets the fluid pressure changeover timing and the initial fluid pressure.