Abstract: A method and apparatus for diagnosing a failure of an output shaft speed sensor of an automatic transmission is provided, which comprises: determining whether a current transmission is a forward driving range; determining whether a failure criterion exists based on a current gear, an input shaft speed, an output shaft speed, and an engine speed, if the current transmission is the forward driving range; and maintaining the current gear if a downshift criterion exists, or upshifting a gear if a upshift criterion exists, if the failure criterion exists.

Abstract: A method is described for control of a CVT automatic transmission (1) in which a sensed main pressure (p_hd_act) and a sensed contact pressure (p_s2_act) of a secondary pulley (7) are entered as signals in an electronic transmission control (8). For diagnosis of an error in the sensing of the main pressure (p_hd_act) and/or of the contact pressure (p_s2_act) of the secondary pulley (7) their actual values or comparison variable (|p_hd_act-p_hd_nom|, |p_s2_act-p_s2_nom|) formed therefrom are compared with applicable threshold values (p_hd_min, pd_phd_regdiff, p_s2_min, pd_ps2_regdiff) associated with a range of plausible pressure values.

Abstract: An automatic transmission comprising a controlling unit 5 for driving and controlling an actuator 3 until a rotation position, which is detected by a potentiometer 13 in response to the receipt of an instruction signal from an operation switch portion 17, accords with the instructed shifting position. The transmission includes a self-diagnosis unit 9 for diagnosing a trouble after driving the actuator 3 to the position over the instructed shifting position for a predetermined amount on the basis of the first instruction signal by the operation switch portion 17 at a starting time of driving an automobile and after driving the actuator 3 in reverse to the instructed shifting position, as well as driving the actuator 3 by varying high or low the duty ratio in driving and controlling the actuator 3, in accordance with the judgment whether or not an output signal of the potentiometer 13 corresponds to such driving.

Abstract: An automatic transmission controller having automatic-shifting-to-neutral control is provided, wherein automatic-shifting-to-neutral control is notified to a driver so as not give him a sense of incongruity and it is prohibited on a slope so as to prevent backward moving of a vehicle. In an automatic transmission controller having automatic-shifting-to-neutral control for shifting the automatic transmission to neutral when a vehicle is continuously stopped in an idling state for a predetermined time, the automatic transmission controller comprises automatic-shifting-to-neutral notifying/warning means for notifying the automatic-shifting-to-neutral state, slope detecting means for detecting that the vehicle is on a slope, and automatic-shifting-to-neutral control prohibiting means for prohibiting the automatic-shifting-to-neutral control when it is detected that the vehicle is on the slope.

Abstract: A method of operating a motor vehicle that is equipped with sensors to detect the rpm-rates of the driven wheels includes the steps of: a) determining current rpm-rates of one or more driven wheels; b) examining the current rpm-rates for potential errors; c) detecting whether a command for a gear shift has been initiated; and d) in case an error was found in step b), taking protective measures so that the engine cannot be forced to run at rpm-rates detrimental to the safe operation of the vehicle as a consequence of executing and completing the gear shift.

Abstract: The invention proceeds from a vehicle having a clutch and a transmission. The clutch is mounted in the drive train of the motor vehicle and the transmission is mounted in the drive train and is changeable with respect to its transmission ratio. Furthermore, means are provided which generate a clutch signal which represents the actuation of the clutch. The essence of the invention is that a change of the transmission ratio is detected. According to the invention, monitoring means are provided by means of which a fault signal is generated in dependence upon the recognized change and the generated clutch signal. The fault signal indicates whether the means, which generates the clutch signal, operates properly. A further variation of the invention evaluates the clutch actuation with the first start of movement of the vehicle after the engine start.

Abstract: The invention relates to a method for controlling a high-temperature operating mode of an automatic transmission wherein at least one value of an actual engine (CMO) or transmission (CGT) temperature is continuously measured. In the electronic control unit several gear shift control programs are stored and are accessed at normal operating temperatures according to an evaluation counter provided with a driving activity characteristic. It is proposed that the evaluation counter be provided with a high-temperature operating value (MAX(UDCHMMO, UDCHMGT)) with which is associated a gear shift program which also has temperature-lowering properties when the actual temperature value (CMO, CGT) is higher than a first limit value (MOMIN, GTMIN).

Abstract: In a conventional abnormality detecting apparatus, it is impossible to judge a breakdown before the breakdown actually takes place. An abnormality detecting apparatus for an automatic speed changer includes a speed change controlling unit for controlling the automatic speed changer; a learn controlling device for optimizing an rpm change at the time of speed change control by the speed change controlling device; and an abnormality detection controlling device for judging whether a learned value of the learn controlling device falls within a range between an upper limit and a lower limit and if the learned value falls out of the range, storing the condition as abnormal. Thus, it is possible to detect the abnormal condition of constituents such as a clutch in the automatic speed changer before the actual breakdown.

Abstract: A method of operating a motor vehicle that is equipped with sensors to detect the rpm-rates of the driven wheels includes the steps of:

Abstract: A shift control method for an automatic transmission includes the steps of determining if upshift conditions are satisfied; determining if throttle valve opening is below a power on/off check line if upshift conditions are satisfied; determining, if throttle valve opening is below the power on/off check line, whether a change in throttle valve opening in a closed direction is less than a predetermined value; and preventing upshifting if the change in throttle valve opening in the closed direction is less than the predetermined value.

Abstract: A fault diagnosis method is provided in which it is possible to determine whether the input shaft speed sensor of the automatic transmission is faulty by using the signals of the output shaft speed sensor, the brake switch, the engine speed sensor and so on, without making use of the signal of the vehicle speed sensor. Moreover, even if there are faults in the output shaft speed sensor or if the shift lever is positioned in the parking P range or the neutral N range, or if the engine speed is lower than the stall speed, the fault diagnosis method for the input shaft speed sensor can be performed, and additionally, a possibility of a misjudgment caused by a bad N-D hydraulic pressure response at an extremely low temperature can be removed.

Abstract: An electronic control system for a transmission in a work vehicle such as an agricultural tractor is provided herein. The system includes sensors for detecting the output speed of the vehicle engine, the output speed of the transmission and the vehicle ground speed. Command devices are available to the vehicle operator for generating command signals, such as for commanding the direction of movement, as well as forward and reverse gear ratios. A controller receives signals from the sensors and command devices, and controls engagement and disengagement of combinations of fluid clutches in the transmission to obtain desired gear ratios between the transmission input and output shafts. The system stores default forward and reverse gear ratios which are used upon start-up of the vehicle. To permit limited modification of the default gear ratios, an interface separate from the vehicle is provided to modify the default gear ratios.

Abstract: For an automatic transmission (2), a safety system is proposed in which a virtual reduction ratio is calculated when a driver moves the selector lever from a drive position to neutral and then from neutral back to a drive position. The virtual reduction ratio is then compared with the reduction ratio resulting from a shift characteristic field. In case of divergence, the virtual reduction ratio is assigned to a characteristic field having a linearly constant reduction ratio surrounded by a reduction ratio range. The electronic control unit (5) selects as a set reduction ratio, the one containing in its range the virtual reduction ratio.

Abstract: The invention provides a linkless steering apparatus for vehicle in which a steering mechanism and steering wheel are not mechanically connected. The steering apparatus drives a steering motor of the steering mechanism in accordance with a steering torque so as to increase or decrease a steering angle. The steering torque for this purpose is calculated based on results obtained by detecting a rotational angle of an electric motor (a reaction-force motor) connected to a rotational shaft of the steering wheel and an electric current flowing to the electric motor, a moment of inertia of the steering wheel, and a moment of inertia of the electric motor. Therefore, it is possible to avoid use of a torque sensor which requires a large space for installation thereof and high cost.

Abstract: An automatic transmission comprising controlling unit 5 for driving and controlling an actuator 3 until a rotation position, which is detected by a potentiometer 13 in response to the receipt of an instruction signal from a operation switch portion 17, accords with the instructed shifting position, characterized by comprising self-diagnosis unit 9 for diagnosing a trouble after driving the actuator 3 to the position over the instructed shifting position for a predetermined amount on the basis of the first instruction signal by the operation switch portion 17 at a starting time of driving an automobile and after driving the actuator 3 in reverse to the instructed shifting position, as well as driving the actuator 3 by varying high or low the duty ratio in driving and controlling the actuator 3, in accordance with the judgment whether or not an output signal of the potentiometer 13 corresponds to driving mentioned above.

Abstract: The invention proceeds from a vehicle having a clutch and a transmission. The clutch is mounted in the drive train of the motor vehicle and the transmission is mounted in the drive train and is changeable with respect to its transmission ratio. Furthermore, means are provided which generate a clutch signal which represents the actuation of the clutch. The essence of the invention is that a change of the transmission ratio is detected. According to the invention, monitoring means are provided by means of which a fault signal is generated in dependence upon the recognized change and the generated clutch signal. The fault signal indicates whether the means, which generates the clutch signal, operates properly. A further variation of the invention evaluates the clutch actuation with the first start of movement of the vehicle after the engine start.

Abstract: A power-assist vehicle such as a wheelchair senses driving torque/force applied by a user through a transmission. The detected force/torque is utilized in a control system with a control map defining a desired dynamic of the vehicle and programmed with the desired mass and drag parameter.

Abstract: A control apparatus for a power train that includes an engine and a motor generator that generates power to a wheel. Furthermore, a clutch is disposed in a power transmission path from the engine to the wheel includes a driving power controller for controlling power generated from the motor generator to the wheel when the clutch fails.

Abstract: An automatic transmission controller having automatic-shifting-to-neutral control is provided, wherein automatic-shifting-to-neutral control is notified to a driver so as not give him a sense of incongruity and it is prohibited on a slope so as to prevent backward moving of a vehicle. In an automatic transmission controller having automatic-shifting-to-neutral control for shifting the automatic transmission to neutral when a vehicle is continuously stopped in an idling state for a predetermined time, the automatic transmission controller comprises automatic-shifting-to-neutral notifying/warning means for notifying the automatic-shifting-to-neutral state, slope detecting means for detecting that the vehicle is on a slope, and automatic-shifting-to-neutral control prohibiting means for prohibiting the automatic-shifting-to-neutral control when it is detected that the vehicle is on the slope.

Abstract: An apparatus and method is provided for preventing sudden acceleration of a vehicle having an automatic transmission by detecting the sudden acceleration with use of transmission state information and rpm. A controller determines that sudden acceleration occurs if the rpm abruptly increases within a first reference time when the transmission maintains a stop or park state, output voltage of an accelerator pedal detected by an ACC detecting unit is less than a predetermined level after inputting a start key. In addition, the controller determines the sudden acceleration if the transmission changes to a driving state and the rpm abruptly increases within a second reference time. When the vehicle drives at a high speed, the controller detects sudden acceleration only when the transmission changes by repeatedly counting the rpm. The controller may also be a central processor unit in an engine control unit of the vehicle.

Abstract: A control system/method to minimize unwanted shifts in an automated mechanical transmission system (12). Initiation of shifts are prohibited unless throttle position (THL) has achieved a substantially steady-state value (|(d/dt(THL))|<REF1≈0).

Abstract: An improved diagnostic control method for a motor vehicle powertrain including an electronically controlled multi-range transmission and a multi-range transfer case, wherein a default determination of transfer case range enables reliable evaluation of transmission ratio, for powertrain configurations with or without a transfer case range indicator switch. An overall speed ratio is computed according to a ratio of the transmission input speed and the transfer case output speed, and the computed ratio is monitored to identify a period of stable operation at the conclusion of transmission shifting and in steady state operation during which the rate of change of the computed ratio is stable over a predefined interval. If the computed ratio is also deemed to be stable, it is compared with an expected overall ratio based on an assumed speed range (low or high) of the transfer case.

Abstract: Disclosed is a fail-safe control method for an automatic transmission having a one-way clutch comprising the steps of determining if shifting into a drive D range is completed; determining if synchronization into a first speed has occurred; and determining if roll-over of a one-way clutch has occurred, and if it has, controlling a friction element of a hydraulic control system so that forced shifting into the first speed is performed.

Abstract: An electronic control system for an automatic transmission has an electronic control unit including a CPU and a memory. The control program is programmed based on an object-oriented programming. An object such as a domain control unit or individual control parts are provided for driving a corresponding linear solenoid valve. A shift request output unit determines types of required shift and outputs a shift request message including the shift type. The domain control unit determines a method to be executed in response to the shift type ID. Preferably, the shift request output unit further determines whether the shift is a single shift or a multiple shift and whether the shift is a normal shift or a special shift. These determination results are also included in the shift request message, so that the domain control unit varies the method to control the linear solenoid valves.

Abstract: A motor vehicle having an electronically controlled automatic transmission, which comprises a parking position, and a power parking brake. The parking position and the power parking brake are operable independently of one another. A redundant system is provided in that a device checks the parking position as well as the power parking brake with respect to its optional functioning and, in the event of an operating failure of one system, operates the respective other system to take over the function of the failed system.

Abstract: The present invention provides a method and apparatus for controlling a work implement in order to enable an earth moving machine to move to a service area after a failure within an implement control system occurs. The method includes the steps of detecting the failure of the implement control system, enabling a limp home mode in response to the failure, and controlling the implement into a limp home position through operator interaction using a display and either an associated keypad or a touch screen.

Abstract: In machines having electro-hydraulic transmission controls, it is desirable to ensure that in the event of an electrical malfunction or power failure the transmission responds appropriately. In the subject invention, a system is provided in a transmission which in the event of an individual clutch solenoid fault (short-to-battery, short-to-ground, and open circuit fault) keeps the machine in gear and protects the transmission from damage. A short-to-battery fault will allow shifting to an available gear that utilizes the faulted clutch. If there is a short-to-ground or open circuit fault then the transmission will latch the current gear or shift to a predetermined gear that does not utilize a faulted clutch.

Abstract: A down-shift is carried out when a) the sum of a dry force of a vehicle and a predetermined value, is smaller than a running resistance, and b) when an accelerator opening is larger than a threshold value which is based on vehicle speed, road inclination, and speed change step (gear position).

Abstract: A method of determining the shift lever position of an electronic automatic transmission system by identifying the mode of transmission operation selected by the driver of the vehicle to provide hysteresis between the park, reverse, neutral, drive and low positions, to permit improved performance and response of the controller and to permit limited operation of the controller upon the occurrence or detection of a fault effecting the performance of the transmission. Such faults include the loss of a PRND2L sensor and the loss of one or more sensors indicative of the dynamics of the vehicle or hydraulic circuit.

Abstract: A system/method of resetting the value of a control parameter (GCWCP) indicative of vehicular gross combined weight and determined as a filtered/averaged value, to a predetermined default value upon sensing vehicle operating conditions (50% GCWCP<GCWTEST or 200% GCWCP>GCWTEST)deemed indicative of a change in vehicle loading. A vehicle automated system, such as an automated mechanical transmission system, is controlled as a function of the value of the control parameter.

Abstract: A method of shifting a transmission having both a hydrostatic portion, including a variable pump (15), and a hydraulic motor (29), and a mechanical transmission (33) portion, including a shift cylinder (37). The method includes relieving the output torque of the motor (29), shifting the mechanical transmission to neutral, and controlling the. displacement of the pump (15) to synchronize motor output speed with the required input speed to the desired gear ratio of the mechanical transmission (33). Then fluid flow to the shift cylinder (37) occurs to shift to the desired gear ratio. The shifting method includes a series of steps in which the feasibility of the prospective shift is determined, and only when the prospective shift can be completed, without detriment to the operation of the vehicle, will the shift be completed. As a result, the shifting between low gear and high gear can occur without bringing the vehicle to a stop each time.

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: A control system/method to minimize unwanted upshifts in an automated mechanical transmission system (12). Upshifts are prohibited unless throttle position (THL) has achieved a substantially steady-state value (.vertline.(d/dt(THL)).vertline.<REF-1) or a speed value (ES, IS, OS) exceeds a reference (OS<REF-2).

Abstract: An automatic transmission control system having gearing that establishes multiple forward driving ratios and a reverse ratio as well as a neutral mode, an electrohydraulic control valve circuit for controlling the application and release of clutch and brake elements for the transmission gearing, a driver-controlled range selector for transmitting operator commands to shift control logic, and a failure mode management circuit that monitors the shift control logic and the response of the transmission system to operator commands, as well as the transmission range selector signals delivered to the shift control logic whereby multiple control redundancies in the electronic range control system ensure that system failures and component failures develop an error signal to alert the driver of possible malfunctions during the range selection period.

Abstract: A gear shift failure of an automatic transmission to a wrong gear other than an indented gear is made by estimating slippage theoretically caused in a torque converter on the basis of an engine speed and a turbine speed theoretically determined for an intended gear according to the vehicle speed and comparing the estimating slippage with predetermined reference slippage. When the estimated slippage exceeds the predetermined threshold slippage, it is decided that there has occurred a wrong shift to a gear other than the intended gear.

Abstract: A control apparatus and method for an automatic transmission that prevents incorrect determination of the start of a gear change inertia phase caused by bounding of an input shaft speed, and that prevents delay of the detection of the start of the inertia phase. A working fluid pressure of the frictional element is feedback-controlled in an inertia phase of a gear change transition of a speed-changing gear mechanism, wherein the input shaft speed of the mechanism changes along with an engaging operation of a frictional element of the mechanism. When it is determined that a starting point for the inertia phase control has been reached, inertia phase control is initiated. After a predetermined determination interval subsequently elapses, it is determined whether the inertia phase control should continue.

Abstract: The invention concerns a method of monitoring the gearshift process in an automatic transmission. In order to be able to recognize fault conditions, the invention proposes in one embodiment that the actual change in transmission ratio is compared with a required change in transmission ratio. In another embodiment the change in the difference in the speed of the rotation of the engaging shift element is examined. It is also possible to analyze the gradient of the difference in the speed of rotation of the engaging shift element. A further possibility is to monitor the gradient of the transmission input speed. In addition, the gradient of the speed at the transmission output can be monitored. As result of the analysis, the transmission ratio is either retained or a predetermined safety condition is brought about.

Abstract: A speed change control system for a synchromesh type transmission includes a synchromesh mechanism having a sleeve ring adapted to be moved in the axial direction of an output shaft to mesh with an idle gear to fix the idle gear on the output shaft, and a shift actuator adapted for acting on a shift fork connected to the sleeve ring, to effect engagement/disengagement between the sleeve ring and the idle gear. A pressure control device is provided for making variable the pressure to be applied to the shift fork by the shift actuator. The pressure control device sets the pressure so high from the speed change start to the balk point that the shift fork is able move as fast as possible and so low from the balk point onward that shift shock is reduced.

Abstract: A display system for an automatic transmission including: a first range switching mechanism for switching a shift range by a mechanical operation; and a second range switching mechanism activated by electric enabling mechanism for switching the shift range by an electric operation. The display system comprises: a first display device for displaying the shift range which is selected by the first range switching mechanism; a second display device for displaying the active state of the enabling mechanism; and a third display device for displaying the shift range which is selected by the second range switching mechanism activated by the enabling mechanism.

Abstract: When the ETV control system runs into trouble, drivability and safety are secured against the system trouble by fixing the step of speed change at a high speed position if the vehicle is running forward or stopping fuel feed to a specific cylinder or cylinders if it is running backward. When the electronic throttle control system runs into trouble, the throttle valve 3 is released from control by stopping power supply to the motor 1, the throttle value 3 is mechanically fixed in a preset position, and the transmission 2 is fixed in a high speed position if the vehicle is running forward, thereby to reduce engine acceleration and the shock to the body due to unnecessary speed change action, or fuel feed to a specific cylinder or cylinders is stopped according to the engine condition if the vehicle is running backward, thereby to reduce the engine output, so that the vehicle be enabled to run smoothly.

Abstract: A compact-sized position detecting switch-combined electronic control unit disposed on the main body of an automatic transmission and used for detecting range positions chosen by a driver during a shifting operation. The control unit has a base board on which a plurality of elements are arranged, including a microcomputer containing an automatic transmission control program, and a position detecting switch whose detecting portion is connected to the microcomputer. The base board and the position detecting switch are disposed in a single case. The position detecting switch has a rotor and a plurality of non-contact sensors disposed on the base board. The microcomputer contains a learning control program for calculating and correcting any positional deviation in the rotational angle of the rotor with respect to each sensor on the basis of signals from the sensors corresponding to rotation of the rotor. Some of the elements on the base board are arranged outside the range of rotation of the rotor.

Abstract: An adapter engages a floor-mounted shift lever of a vehicle. The adapter holds the locking detent of the shift lever down so that the lever can be moved. A robotic actuator is coupled to the adapter via a ball joint to selectively move the shift lever.

Abstract: For an automatic gearbox (2) a safety system is proposed in which erroneous releasing of the clutch or brake during cross-over is detected by the fact that the time variations of the transmission input speed and of the product of the transmission output speed multiplied by the first reduction ratio do not increase.

Abstract: There are prevented shocks that will occur when a switchover speed changing is made to transfer from one speed changing, in the midst of that speed changing, to another speed changing when the input and output speed ratio "Gratio", which serves a control parameter, is not accurately detected. For that purpose, there is used a flag FGFAIL for setting "1" when the input and output speed ratio "Gratio", at the time of non-speed changing, does not lie within a predetermined range based on the gear ratio of the speed stage that is being established at that time. A switchover speed changing in which switching to another speed changing is made during a speed changing is prohibited when FGFAIL=1.

Abstract: A current control system for a linear solenoid for feedback-controlling an output voltage value on the basis of a difference between a command current value to the linear solenoid, as set according to a vehicle running state, and a feedback current value, as produced by monitoring a current value to be really fed to the linear solenoid, including: a decision circuit that decides whether or not the resistance value of the linear solenoid can be calculated; a real resistance value calculating circuit that calculates a real resistance value on the basis of a signal coming from the decision circuit, the command current value and the output voltage value; a comparison circuit that compares the calculated real resistance value and a resistance value in a memory unit; and a correction circuit that corrects the resistance value in the memory unit on the basis of the comparison result from the comparison circuit. The output voltage value is outputted on the basis of the corrected resistance value.

Abstract: In an automatic transmission in which the electronic control instrument (13) detects, outside the circuits, a fault in the input values (18 to 20), the couplings and the brakes (A to F). When a fault is present for an extended period, the electronic control instrument (13) detects a symptom and switches to a replacement gear. Hereby maximum driveability is ensured without a diagnosis entry.

Abstract: A method of shifting in a manual mode of an electronically-controlled automatic transmission system includes the steps of determining whether a shift lever of a shift lever mechanism is presenting a position error when the shift lever is in a manual position, determining whether at least one switch on the shift, lever mechanism is presenting an error if a shift lever position, error is not determined, determining whether a temperature of an, automatic transmission or engine coolant temperature exceeds a predetermined threshold if the at least one switch is not presenting an error, determining whether the manual position conditions have been met, determining whether an upshift or downshift of the automatic transmission is scheduled if the manual position conditions have been met, and executing either an upshift or a downshift of the automatic transmission based on the determined upshift or downshift being scheduled.

Abstract: A degraded mode of operation (FIG. 7) for a partially automated mechanical transmission system (92) having a splitter-type mechanical transmission (10) with a splitter section (14) automatically shifted in only certain ratios (ninth/tenth). Upon sensing certain system faults when in this automatic splitter shifting mode, the splitter section is retained, as is, until main section neutral can be confirmed, at which time the splitter section is returned to manual control for all transmission ratios.

Abstract: A safe drive support system includes a memory unit for storing road-map data including a safe driving area data, a present location detecting unit for detecting a present location of the vehicle, a determining unit for determining as to whether the present location of the vehicle is in the safe driving area according to a detection result by the present location detecting unit, and limiting unit for limiting driving torque or starting torque of the vehicle in the area according to a determination result by the determining unit. In the safe driving area, the limiting operation is carried out by, for example, setting the gear position of start to the second position so as to prevent the vehicle from starting suddenly. An operational angle of a throttle valve is limited at a predetermined angle to limit the output of the engine to suppress an excess speed when an accelerator is stepped on strongly.

Abstract: A multi-ratio automatic transmission has a plurality of fluid operated clutching devices, a fluidic torque converter and a fluid operated torque converter clutch mechanism. During certain operational periods, a hot mode is invoked to eliminate certain heat sources and increase heat dissipation to thereby prevent the fluid temperature from exceeding a predetermined maximum temperature. The hot mode is invoked as a function of both the temperature of the transmission fluid and the rate of change of the fluid temperature.