Abstract:
A hydraulic pressure system for a frictional engaging element such as clutches for a vehicle automatic transmission. The engagement state of the clutches is detected from the clutch slip rate, and the desired change rate of the rotational speed of the transmission input shaft (the main shaft rotational speed) during the gearshift operation period is varied based thereon. The hydraulic pressures supplied to the clutches are controlled for bringing the actual rotational speed change rate to the desired value. Since the clutch engagement state can therefore be controlled based on the desired value, irrespective of the temperature of the oil (ATF) and aging of the clutches, it is at all times possible to secure optimum gearshift characteristics and to avoid the occurrence of gearshift shock.
Abstract:
To detect the shift position of a motor vehicle transmission (1), the invention teaches that by means of sensors (17), the position of a shift lever (7) which shifts the transmission (1) is measured in the neutral path of a shift pattern of the transmission which corresponds to the neutral position of the transmission (1). The direction of the displacement into the gears which are located in pairs in the shift paths of the transmission is measured by means of shift lever contacts (23), which respond when the shift lever (7) is displaced from the neutral shift position. An evaluation circuit (25), as a function of the signals from the sensors (17) which, in the neutral shift position of the transmission, detect the shift path which has been selected and the signals from the shift lever contacts (23) which detect the direction of displacement, delivers a shift position signal which identifies the shift position instantaneously engaged. The speed ratio of the input shaft (3) and the output shaft (5) of the transmission (1) determined by means of speed sensors (33, 35) is compared in the evaluation circuit (25) to the transmission ratio specified by the design of the transmission for the shift position selected. When the speed ratios coincide, the gear is assumed to be engaged. Since in the transmission (1), only the shift position of the shift lever (7) in the neutral shift position is monitored, the sensors or switches (17) used for this purpose can have large actuation range tolerances.
Abstract:
A multiple ratio transmission having a main gear unit with at least three forward driving ratios and a single reverse drive ratio and a simple planetary gear unit in series with the main gear unit, the simple planetary gear unit being downshifted and the main gear unit being upshifted on an upshift from a first intermediate ratio to a higher intermediate ratio, the simple planetary gear unit being upshifted and the main gear unit being downshifted on a downshift from the higher intermediate ratio to the first intermediate ratio.
Abstract:
An electronic engine control controls the selection and confirmation of automatically selectable gears in a manual/automatic transmission. Failure to disengage the engine from the transmission within a predetermined time period, failure to reach a predetermined synchronous engine RPM window within another predetermined time period and failure to confirm gear engagement within yet another predetermined time period are three automatic shift failure modes which may cause an automatic shift attempt to fail or be aborted. A fourth automatic shift failure may occur if the clutch pedal is depressed during an automatic shift attempt. If any of the foregoing automatic shift failure mechanisms is detected, an error recovery algorithm which forms a part of the present invention determines the easiest/safest transmission gear to command to prevent the driver from having to manually attempt to engage the transmission after a failed automatic shift attempt.
Abstract:
A diagnostic system is provided for detecting a fault condition in a transmission having a plurality of rotating components, a plurality of clutches, and a transmission control. The diagnostic system includes speed sensors producing speed and direction signals representative of the rotational velocity of the rotating components, a processor for calculating the relative rotational speed between two or more clutches and for indicating a fault condition in response to the relative rotational speed and a period of time.
Abstract:
A procedure to control the drive unit in motor vehicles wherein: the maximum engine performance characteristic is determined; as a minimum engine performance characteristic, a reference performance characteristic is specified by how drive resistance depends on vehicle speed at a medium payload of the motor vehicle; above the reference performance characteristic, a first performance characteristic which is dependent on actual driving speed is defined and allocated a minimum assessment value; between this first performance characteristic and the maximum engine performance characteristic, a second performance characteristic which is also dependent on actual driving speed is defined and allocated a maximum assessment value; the current engine performance is determined; current assessment values are determined by comparing current engine performance to the first performance characteristic and the second performance characteristic; the current assessment values, as continuously determined, are filtered over time in this way, filtered assessment values are obtained; and these filtered assessment values are used to select drive unit control parameters, or parameter sets, which then are used to control the drive unit.
Abstract:
A motor vehicle has a driving engine, a clutch, an engine rpm transducer, a transmission, at least one driven wheel, and at least one speed transducer, in particular for ascertaining a vehicle speed or a power take off rpm of the transmission. The at least one speed transducer is equipped with a transducer wheel having one of a first and a second given number of teeth. An electronic control unit includes a clutch recognition device supplying a clutch signal when the clutch is engaged. A calculation circuit ascertains a ratio between the engine rpm and the vehicle speed. A comparator compares the ratio with a predetermined threshold value and supplies an output signal associated with the transducer wheel having the second given number of teeth if the ratio is less than the threshold value. A memory provides nonvolatile storage of the output signal if the clutch signal and the output signal are simultaneously present. The vehicle speed is ascertained from the number of teeth of the transducer wheel associated with the output signal stored in nonvolatile memory, or the number of teeth associated with a specified signal associated with a transducer wheel having the first given number of teeth, if the output signal stored in nonvolatile memory is not present.
Abstract:
A control system for an automatic transmission is constructed so that when failing to detect an operation of skid reduction control, an optimum hydraulic pressure value is determined based on a basic line pressure determined by throttle opening degrees, etc. and a correction value thereof, and an optimum hydraulic pressure signal is provided to a hydraulic pressure adjusting actuator. At this time, the correction value is modified so that a shift time upon current shift approaches a reference shift time. On the other hand, when detecting an operation of skid reduction control, at least modification of the correction value is prohibited.
Abstract:
An automatic transmission control system providing a neutral control state in which there is no slipping engagement of a first clutch which is engaged upon selection of a forward range and, as a result, the vehicle is not subjected to idling vibration. The fuel consumption reducing effect of the neutral control state is maintained and there is no heating and consequent deterioration of the friction material of the clutch. The control system includes a hydraulic servo for operation of the clutch, an input side speed sensor for detecting the input side speed of a fluid power coupling device connecting the transmission to the output of an engine, an output side speed sensor for detecting the output side speed of the fluid power coupling device, and a controller. The controller includes differential speed calculator, differential speed change detector, a pressure increasing device for increasing the hydraulic pressure of the hydraulic servo by a set pressure when the differential speed has not changed, and a pressure reducing device for reducing the hydraulic pressure of the hydraulic servo by a set pressure when the differential speed has changed.
Abstract:
A control system/method for controlling a vehicular, at least partially automated system (110) separate from the vehicular transmission system (10), such as a CTIS or ABS, is provided. The at least partially automated system is controlled as a function of a value (GCW) approximating vehicle gross combined weight and determined as a function of information on the vehicle electronic data link (DL).