Showing papers on "Automatic transmission published in 1998"

Hydraulic control system for automatic transmission

Abstract: When a vehicle driving state of an automatic transmission is changed to a power-off state from a power-on state during a down shift involving the disengagement of one friction element and the engagement of another friction element, a disengagement side pressure PA is reduced rapidly by a feedback control based on the change in gear ratio because of a reduction of an input torque. The disengagement side pressure control is unable to complete change of the gear ratio to complete the down shift. When the disengagement side pressure is reduced to a value less than a return spring load pressure PG or when the gear ratio change has not achieved a basic value in a predetermined time, the down shift control is changed from primary control by the disengagement side pressure control to primary control by an engagement side control so that the gear ratio change is completed by control of the engagement side pressure.

How Automatic Is Manual Gear Shifting

Abstract: Manual gear shifting is often used as an example of an automated (vs. controlled) process in driving. The present study provided an empirical evaluation of this assumption by evaluating sign detection and recall performance of novice and experienced drivers driving manual shift and automatic transmission cars in a downtown area requiring frequent gear shifting. The results showed that manual gear shifting significantly impaired sign detection performance of novice drivers using manual gears compared with novice drivers using an automatic transmission, whereas no such differences existed between the two transmission types for experienced drivers. The results clearly demonstrate that manual gear shifting is a complex psychomotor skill that is not easily (or quickly) automated and that until it becomes automated, it is an attention-demanding task that may impair other monitoring aspects of driving performance. Actual or potential applications of this research include a reevaluation of the learning process in driving and the need for phased instruction in driving from automatic gears to manual gears.

All wheel drive continuously variable transmission having dual mode operation

Abstract: An automatic transmission for an automotive vehicle includes a continually variable drive mechanism having one sheave assembly fixed to an intermediate shaft and the input sheave assembly supported on an input shaft, a low speed gearset driveably connected to the input shaft and an output shaft, a fixed ratio drive mechanism in the form of a chain drive providing a torque delivery path between the intermediate shaft and the carrier of the gearset, a transfer clutch for connecting and releasing the first sheave of the variable drive mechanism and input shaft, a low brake, a reverse gearset, a reverse brake, and a clutch for selectively driveably connecting the output of the fixed drive mechanism and a front output shaft.

Power transmitting system for a hybrid motor vehicle

Abstract: The system has an engine (1), and a planetary gear (3). The planetary gear (3) has a sun gear (3a), a carrier (3b) rotatably supporting a plurality of pinions (3d) each of which engages with the sun gear (3a), a ring gear (3c) engaging with the pinions (3d). A first motor (2) is connected to an output shaft (1a) of the engine (1) and the sun gear (3a) of the planetary gear (3). The first motor (2) is capable of using as a driving source and as a power generator. A second motor (4) is connected to the ring gear (3c). The second motor (4) is also capable of using as a driving source and as a power generator. An automatic transmission (5) is connected between the carrier (3b) of the planetary gear (3) and an axle (8) of a hybrid motor vehicle.

Vehicle motive force control system

Abstract: A system for controlling motive force of a vehicle having an engine and a continuously variable automatic transmission connected to the engine to transmit engine torque to a drive shaft of the vehicle. In the system, a desired motive force is calculated or determined from the detected accelerator (pedal) position and vehicle speed, and based on the determined motive force a desired engine speed, more specifically a drive shaft speed of the transmission, is calculated or determined. Then inertia torque acting on the vehicle is calculated or determined based on at least the determined speed and detected speed, and a desired throttle opening is corrected by the determined inertia torque when the vehicle accelerates or decelerates. With the arrangement, the vehicle response delay due to the inertia torque is adjusted and hence, drivability and fuel economy performance are enhanced.

Shifting device for an automatic transmission

Abstract: A shifting device for an automatic transmission of a vehicle has a manual shift mode which permits a driver to manually change a speed ratio by displacing a shift lever in an upshift direction or a downshift direction in a manual operation lane from its neutral position. The shifting device is provided with a switch for detecting that the shift lever has moved to the manual operation lane, a switch for detecting that the shift lever has moved in the upshift direction from its neutral position, and a switch for detecting that the shift lever has moved in the downshift direction from its neutral position. All these three switches comprise a traveling contact and two contacts. The traveling contacts of the three switches are earthed, and the six contacts of the three switches are respectively connected to six input terminals of a control unit. Due to this, the control unit can determine a fault in any of the switches based on the signals input into the input terminals.

System and method for controlling downhill vehicle operation

Abstract: A system for controlling downhill vehicle operation includes an electronically actuatable engine compression brake unit associated with an internal combustion engine, an electronically controllable turbocharger boost pressure adjustment device, electronically actuatable service brakes and a transmission including a number of automatically selectable gear ratios, wherein each of these components are coupled to a control computer. In accordance with one aspect of the present invention, the control computer is operable to detect a potential runaway vehicle condition and control any one or combination of engine compression brake activity, turbocharger boost pressure, service brake activity and automatic transmission shifting to thereby provide for a controlled descent down a negative grade and thereby prevent a runaway vehicle condition. In accordance with another aspect of the present invention, the control computer is operable to determine a target engine or vehicle speed and control engine or vehicle speed to the target speed, regardless of whether a potential runaway vehicle condition exists, using any one or more of the foregoing control techniques.

Tribology of automatic transmission fluid

Abstract: Various properties are required in the latest ATFs (Automatic Transmission Fluids) because of the progress made in ATs (Automatic Transmissions). In this paper, we will introduce the construction of the AT and describe the tribological issues, including anti‐shudder property, of ATF.

Automatic transmission of voice-to-text converted voice message

Abstract: A voice messaging system includes an input device to accept a destination electronic messaging address, a voice-to-text converter to convert or transcribe a received voice message into a converted text message, and a processor to operate an electronic messaging program and to prepare the text message for automatic electronic transmission to the destination electronic messaging address. A method is also provided to convert a voice message into a text message and to transmit the same to a destination electronic messaging address. The method includes inputting a destination electronic messaging address. A received voice message is converted or transcribed into a text message and prepared as a text file. The prepared text file is automatically transmitted to the destination electronic messaging address. A log file including the text of the voice messages may be maintained with updates at a predetermined time interval. A database of the converted text messages may be generated and maintained to provide a searchable mechanism of archived messages.

Engine stop control device for vehicle

Abstract: PROBLEM TO BE SOLVED: To enable a person not to feel engaging shock in an engine restarting. SOLUTION: In relation to a vehicle which is stopped under a specified stopping condition and in which an engine is restarted under a specified restarting condition, in an engine stop control device for a vehicle in which when the engine is automatically stopped a motor-driven pump is driven to continue the supply of working fluid to an automatic transmission, whether the present state satisfies the operating condition of the motor-driven pump or not, is judged (step 102, 103), and when it is judged that the present state does not satisfy the operating condition of the pump, automatic engine stop control caused by the formation of the specified stopping condition is prohibited. COPYRIGHT: (C)2000,JPO

Electronic control of transmission line pressure

Abstract: A method and apparatus are provided for controlling the hydraulic line pressure in an automatic transmission for a vehicle in response to the measured pressure and torque transmitted through the transmission such that a minimum hydraulic line pressure is provided to the frictional elements to achieve a non-slip condition through the transmission which increases transmission efficiency and fuel economy. Hydraulic line pressure is controlled by activating a solenoid activated valve. Control signals are based on measured hydraulic line pressure, engine speed, turbine speed, vehicle speed, driver selected gear, and torque converter operating condition for the solenoid actuated valve. The present invention further provides a closed-loop adaptive control technology to learn the minimum line pressure to compensate for variability in the clutch return springs, friction characteristics, surface finishes, as well as hydraulic wear, and changes over the life of the transmission. Further, when one of the line pressure components fails, the method provides open loop control.

Integrated control system for electronically-controlled engine and automatic transmission

Abstract: An integrated control system for both an electronically-controlled engine and a steplessly variable automatic transmission, comprises a speed-change ratio arithmetic processing section for calculating the speed-change ratio as a ratio of the transmission input speed to the transmission output speed, a target driving torque arithmetic processing section for retrieving a target driving torque, based on both the accelerator operating amount and the vehicle speed, from a first predetermined characteristic map, and a target speed-change ratio arithmetic processing section for retrieving a target speed-change ratio, based on both the accelerator operating amount and the vehicle speed, from a second predetermined characteristic map. Also provided is a target engine output torque arithmetic processing section for calculating a target engine output torque, based on all of the target driving torque, the speed-change ratio, and a speed ratio of the transmission input speed to the engine speed. Depending on the engine speed and the target engine output torque, the throttle opening and the transmission input speed are both feedback-controlled.

Control system of vehicle driving system

Abstract: In a vehicle driving unit employing a driving source formed by combining an engine with a motor generator, a control system prevents a sharp decline of an output torque of a transmission at the end of a shift operation without extending a time period required for the shift operation. The shift shock resulting from the sharp decline of the output torque can be eliminated. The vehicle driving unit is provided with an engine, a motor generator and a multi-stage automatic transmission for accomplishing a predetermined speed by engagement of friction engagement elements. The control system includes a shift operation termination determination step for determining the length of time remaining until the termination of a shift operation being performed by engagement of the friction engagement elements and a torque output command step for generating a torque assistance command to the motor generator based on the determination made during the shift operation termination determination step such that the transmission output torque decreases gently from a predetermined torque value. An assistance torque is outputted to prevent the sharp decline of the transmission output torque at the end of the shift operation caused by the inertia torque being rapidly absorbed by the friction engagement elements.

Working fluid supply system for automatic transmission

Abstract: PROBLEM TO BE SOLVED: To ensure necessary supply of working fluid to an automatic transmission during an engine stop while minimizing the battery power consumption, and reduce the size of an engine-driven mechanical pump. SOLUTION: This working fluid supply system comprises a mechanical oil pump 12 driven by an engine 1, an electric oil pump 15 driven by a motor generator 6, and control means (a hydraulic control device 20 and a controller 33) for controlling the supply of working fluid. The control means drives only the mechanical oil pump 12 while the engine 1 runs a high sped. While the engine 1 runs at low speed, on the other hand, the control means drives not only the mechanical oil pump 12 but also the electric oil pump 15 to make up a flow-rate undersupply of the mechanical oil pump 12. While the engine 1 is stopped, only the electric oil pump 15 is driven.

Control device and control method for automatic transmission

Abstract: PROBLEM TO BE SOLVED: To smoothly shift up without imparting a sense of incompatibility to an occupant by synchronizing an output shaft rotating speed with an engine speed at the shift-up time by controlling an electronic control throttle valve, and smoothly changing clutch oil pressure of a high speed side shift stage. SOLUTION: In a transmission, a first speed and a second speed are established by fastening/releasing a driving gear 112 to/from an output shaft 105, and a third speed to a fifth speed are established by fastening/releasing a drive gear to/from an input shaft 104. The first speed to the fourth speed are fastened/ released to a shaft by a synchronizer mechanism 117, and the mechanism 117 is operated by a shift fork 110 controlled by a shift cylinder 108 and a select cylinder 109. In this case, at shift-up time, an output shaft rotating speed and an engine speed are synchronized by control of an electronic control throttle valve 120, and clutch oil pressure of the fifth speed is smoothly changed to high speed side torque from low speed side torque to guarantee a smooth shift.

Control apparatus and method for powertrain of a vehicle

Abstract: A control apparatus and method for a powertrain of a vehicle provided with a drive unit which has the powertrain including an engine or an electric motor and an automatic transmission, and a driving shaft. The control apparatus is provided with first torque estimating means for obtaining a first estimated driving shaft torque, second torque estimating unit for obtaining a second estimated driving shaft torque used to correct said first estimated driving shaft torque, comparison means for comparing said first estimated driving shaft torque with said second estimated driving shaft torque, and driving shaft torque calculating means for calculating a driving shaft torque on the basis of the result of the comparison.

The Selection of a Most Efficient Clutching Sequence Associated With Automatic Transmission Mechanisms

Abstract: This paper presents a methodology for the identification of a most promising clutching sequence associated with an epicyclic-type automatic transmission mechanism. First, a methodology for the analysis of torque distribution on the links of an epicyclic gear mechanism is described. Then, the power loss relations associated with various clutching sequences of an epicyclic gear mechanism are derived. Finally, a procedure for the selection ofa most efficient clutching sequence associated with a transmission mechanism is developed.

Oil pressure supply device for vehicle drive system

Abstract: An engine and a motor are connected to the drive wheels of a vehicle via an automatic transmission. The drive wheels are driven using one of or both of the motor and the engine depending on the running state. The automatic transmission varies the drive ratio by the discharge pressure of the oil pressure pump. The oil pressure pump is driven by a second motor. When the automatic transmission is varying the drive ratio, the discharge of the oil pressure pump is increased by increasing the rotational speed of the second motor and thus the required oil for varying the drive ratio is maintained.

Controller for an automatic transmission in a motor vehicle

Abstract: The controller is used, in particular, for controlling an automatic transmission in a motor vehicle. An actuation signal is defined and used to determine the gear speed which is to be selected or the transmission ratio which is to be set. The actuation signal is a function of the position of the accelerator pedal, of the vehicle speed or, possibly, of further measured of variables. The controller includes a classification system which receives the measured variables and parameters derived therefrom as input variables and which generates output variables with reference to an evaluation of the measured variables and parameters. The output variables take into account certain assignments of the driving behavior of the driver, the respective driving state or the respective load state of the motor vehicle. The controller contains an evaluation circuit in which an intervention signal, which is generated by manual intervention by the driver, is evaluated and, subsequent thereto, one of the prescribed assignments is modified by emitting an evaluation signal. In this context, subfunctions of the controller can be switched off or important stored parameters of subfunctions can be modified without entirely deactivating them.

Vent system for an automatic transmission

Abstract: A vent system for an automatic transmission includes a front body assembly connected to a housing of the automatic transmission and a connecting tube having a first end and a second end, the first end being connected to the front body assembly. The vent system also includes a rear body assembly connected to the housing and to the second end. The vent system allows ingress and egress of air between inside and outside of the automatic transmission and prevents ingress of moisture/water and egress of transmission fluid.

Parking lock for automobile automatic drive transmission

Abstract: The parking lock uses a locking element which blocks the automatic transmission upon operation of the parking lock, the locking element acted on by a spring-loaded hydraulic cylinder (4) via a pivoted setting lever (1). This cooperates with an electromagnet (11) via an intermediate lever (12), for preventing operation of the parking lock when the gear selection lever is in the neutral position.

Cruise control system for motor vehicle

Abstract: A motor vehicle is provided with an automatic transmission including a shift manipulating device having an automatic shift position and a manual shift position, and a shift control device which places the automatic transmission in an optimum gear position when the shift manipulating device is operated to the automatic shift position, and places the transmission in a desired gear position according to a shift command operation by a driver when the shift manipulating device is operated to the manual shift position. The cruise control system includes a target speed setting device which sets a target speed to which a vehicle speed is controlled under constant-speed cruise control, a vehicle speed sensor which detects a vehicle speed, a constant-speed cruise control device which controls an engine of the vehicle so that the vehicle speed detected by the vehicle sensor becomes equal to the target vehicle speed set by the target vehicle speed setting device, and a canceling device which cancels an operation of the constant-speed cruise control device means when the shift manipulating device is operated from the automatic shift position to the manual shift position, and the transmission is shifted to a different gear position, while the vehicle is running under constant-speed cruise control.

Toroidal type automatic transmission for motor vehicles

Abstract: Even in the case where a driver switches a select lever from D range to N range and returns it back to D range during the running of a vehicle, a speed change control device prevents the operation of sudden speed change caused by a difference between a transmission input rotational speed and the actual input rotating speed of a toroidal transmission unit while in the N range. Accordingly, an automatic transmission comprises a forward-reverse switching mechanism, an impelling mechanism and a toroidal transmission unit which are sequentially arranged from the driving source side of a vehicle, and further comprises a speed change control device for controlling the operation of the above. A notch as a rotational speed signaling section is provided on the outer periphery of a loading cam, for example, among rotating members in the area from an output member of the above forward-reverse switching mechanism to an input disc of the above toroidal transmission unit, and the notch is detected by a rotation sensor arranged in the vicinity of the outer periphery to detect the rotational speed of the loading cam and input the same to the speed change control device.

Hydraulic control device for automatic transmission

Abstract: PROBLEM TO BE SOLVED: To eliminate a restriction on a pressure regulating valve setting position so as to ensure freedom of valve layout in a hydraulic control device for an automatic transmission leading drain oil from the pressure regulating valve directly to an inlet port of an oil pump without passing through an oil strainer. SOLUTION: In this hydraulic control device, a valve body is composed of three stage valve bodies 43, 44, 45 laminated and connected through separating plates 41, 42, and a pressure regulating valve 5 is provided at the middle stage valve body 44 other than the lowermost stage one out of three stage valve bodies 43, 44, 45. A drain port of the pressure regulating valve 5 is communicated with an inlet oil passage 2 leading to an inlet port 1a, through a drain hole 22 of the separating plate 42 and a drain hole 23 of the lower stage valve body 45.

Closed-loop adaptive fuzzy logic hydraulic pressure control for an automatic transmission

Abstract: 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.

Interactive engine and automatic transmission control

Abstract: An interactive engine and automatic transmission control system is provided wherein spark and air control are used to control engine speed to maintain a small positive torque on the transmission before and after coast down shifts. More particularly, a transmission controller is electrically coupled to an engine controller in a motor vehicle such that information can be passed therebetween. Such information includes a start of shift signal, a phase of the shift signal (i.e., clutch release phase, speed change phase, or clutch application phase), and a shift complete signal. In addition, the transmission controller identifies the type of shift that is occurring (i.e., fourth gear to third, third to second, or second to first), transmission oil temperature and the acceleration (braking) rate of the vehicle to the engine controller. During the three phases of a coast down shift, air flow control is used to supply an appropriate amount of air to the engine so that closed loop spark control can be used to adjust the speed of the engine. By maintaining the engine speed slightly above the turbine speed just before and just after a coast down shift, very little torque is transmitted through the transmission during the shift. As such, the coast down shift is practically imperceivable to the driver.

Device for controlling an automatic transmission of a motor vehicle

Abstract: The device contains an electronic control system, which, in an automatic mode, automatically determines the transmission ratio in dependence of an operating condition, and contains selector devices, which, in the automatic mode, determine the driving stages of the transmission control and, in a manual mode, change the transmission ratio in steps. After a manual selection of the transmission ratio, driving and operating situations in which the automatic mode of the control system is desirable are detected and, if such a situation is detected, a return circuit causes the electronic control system to return to the automatic mode.

Neutral control device of automatic transmission

Abstract: PROBLEM TO BE SOLVED: To improve the fuel consumption saving effect and lessen a feeling of a physical disorder given to a driver by shifting an automatic transmission to the neutral condition when it is totally judged that an accelerator opening is a designated value or less, a brake is actuated, it is shift-down timing, and a car speed is a prescribed value or less. SOLUTION: The respective signals of a range detecting means 3, an accel opening detecting means 4, a brake operation detecting means 5, a shift-down detecting means 6, a car speed detecting means 7, an engine cooling water temperature detecting means 8, and a transmission oil temperature detecting means 9 are input to a control means 2. In the case where the shift range is forward running, under the main conditions that (a) the accelerator opening is a prescribed value or less, (b) the brake is in the actuating state, (c) it is shift-down timing, and (d) the car speed is a prescribed value or less, an automatic transmission 1 is set to the neutral condition to prevent creeping. When the engine cooling water temperature and the transmission oil temperature are designated values or less, the transition to the neutral condition is inhibited. Thus, the fuel consumption saving effect can be improved, and a feeling of physical disorder given to a driver can be lessened. COPYRIGHT: (C)1999,JPO