Abstract: A transmission includes a transmission input speed sensor which generates transmission input speed signals indicative of an input speed to the transmission and a transmission output speed sensor which generates transmission output speed signals indicative of an output speed of the transmission. The transmission further includes a controller operable to receive the transmission input speed signal and the transmission output speed signal and determine a transmission ratio based on the transmission input speed signal and the transmission output speed signal. The controller is further operable to calculate a rate of change of the transmission ratio and initiate a transmission range shift based on the transmission ratio, the rate, and a shift completion ratio such that the transmission range shift is completed when the transmission is at the predetermined shift completion ratio.

Abstract: In a vehicle continuously variable transmission, an engine rotation speed, input rotation speed of the transmission and an output rotation speed of the transmission are respectively detected by sensors (64, 65, 68). Based on the output signals from these rotation speed sensors (64, 65, 68), a controller (61) controls a speed ratio of the transmission within a predetermined speed ratio range. The controller (61) also determines if any of the rotation speed sensors (64, 65, 68) has an abnormality based on the output signals from these sensors (64, 65, 68) and narrows the predetermined speed ratio range (S234) when any of the sensors has been determined to have an abnormality, so as to prevent an extraordinary speed ratio control from being performed.

Abstract: The present invention provides a vehicle travelling control apparatus for a vehicle with an HST and a mechanical transmission, which are connected in tandem to each other and interposed in a travelling power transmission path between a driving power source and driving wheels. The vehicle travelling control apparatus includes a speed-change control mechanism which in turn includes a signal detection part and a control part for controlling the changing of the output speed of the HST and the shifting operation of the mechanical transmission. The signal detection part includes a load-torque detection means for detecting the load torque with respect to the vehicle. The control part is designed to control the mechanical transmission and the HST based upon the detected results by the load-torque detection means so that where the vehicle lies in a high load torque state, the control part downshifts the mechanical transmission to a lower speed stage, while increasing the output speed of the HST.

Abstract: A traveling mechanism having a driving motor (24) which drives a feed pump (25) and a hydrostatic variable displacement pump (2), a zero fluctuating hydrostatic variable displacement motor (1) which forms with the hydrostatic variable displacement pump (2) a hydrostatic circuit and a hydrostatically driven 2-speed gear mechanism (11) which is engaged when the torque to be transmitted is minimal and the hydrostatic variable displacement motor (1) is at zero displacement capacity.

Abstract: A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates an actual velocity signal in response measuring speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device, or speed pedal, which is positionable in one of an infinite number of positions and generates a desired velocity signal corresponding to the position of the speed pedal. The control apparatus yet further includes a controller operable to receive the desired velocity signal, receive the actual velocity signal, calculate a commanded acceleration ac, and generate a commanded velocity Vc based on the desired velocity signal, a jerk value j, and the commanded acceleration ac. A method of controlling a continuously variable transmission is also disclosed.

Abstract: A control for an automatic shifting power transmission employs an algorithm to determine the proper gear ratio during vehicle deceleration. The algorithm establishes downshift grade requirements based on the brake pressure and speed threshold targets based on brake pressure. A grade average is calculated from the operating parameters of acceleration, engine braking, aerodynamic drag, rolling resistance and brake torque deceleration. If the grade average is within downshifting range and the speed target is met, the control commands a downshift to the next lower gear ratio. The downshift grade requirements decrease as brake pressure increases and speed targets increase as brake pressure increases.

Abstract: A controller (61) calculates a transient target speed ratio based on a final speed ratio set according to a vehicle running condition and second order delay time constant gains (75, S99), and control a speed ratio of a continuously variable transmission to the transient target speed ratio via an actuator (4) (87, S103). The controller (61) also calculates the deviation between the final target speed ratio and transient target speed ratio (74, S95), and determines the second order delay time constant gains based on the deviation (74, S98). Preferably, the gains are determined so that the response rate is slower the larger the deviation (74, S134, S135, S136, S137, S139, S140, S141).

Abstract: A hydrostatic/mechanical multiple path power transmission comprises an adjustable hydrostat unit (4), a summing planetary gearbox (10) with two input shafts (6, 8) and at least two output shafts, and a step gearbox (11) connected to the output shafts. In order to adjust low speeds and standstill precisely and rapidly, the following method is specified: rotational speed signals are formed by sensors (50, 51) on the two input shafts (6, 8) of the summing planetary gearbox (10), and are compared with each other by counters (61, 62); the actual pulse count difference formed in this way is compared with a desired pulse count difference, and a controller [sic] and the output signal of a controller (66) that responds to the result of this comparison effects adjustment of the hydrostat (4).

Abstract: In a speed change ratio controller of a continuously variable transmission, a speed change ratio varying mechanism which varies a speed change ratio and a speed change ratio servo device which controls this speed change ratio varying mechanism according to a signal from a microprocessor, are provided. The microprocessor sets a final speed change ratio according to the vehicle traveling conditions, and computes a deviation between the final speed change ratio and target speed change ratio. A target dynamic characteristic parameter of the speed change ratio is set according to this deviation, and the target speed change ratio and a command speed change ratio are computed based on the final speed change ratio and target dynamic characteristic parameter. By outputting the command speed change ratio obtained in this way as a signal to the speed change ratio servo device, high response speed change ratio control is achieved.

Abstract: The method for eliminating an oscillation phenomenon in a motor vehicle with an automatic transmission system. The mass of the vehicle is determined on the basis of the measured speed, the current ratio of the transmission, the engine speed and the opening angle of the engine throttle. The acceleration of the vehicle and a higher ratio is predicted from the mass of the vehicle. The total amount of tractive resistance applied to the vehicle is determined. The probability that there will be an oscillation phenomenon at a higher ratio termed "oscillation risk" is determined from the acceleration and tractive resistance information. A signal for preventing shifting to the higher ratio is generated from the oscillation risk information, with the signal being adapted to be applied to a transmission control device.

Abstract: A control apparatus for a continuously variable transmission is disclosed. The control apparatus includes a transmission speed sensor which generates actual velocity signals in response measuring a speed of an output shaft of the continuously variable transmission. The control apparatus further includes a first input device which is positionable in one of a number of positions and generates a desired velocity signal corresponding to the one of the number of positions. The control apparatus yet further includes a controller operable to receive the desired velocity signals, receive the actual velocity signals, determine when rapid changes in the desired velocity are requested by an operator, and generate a commanded acceleration and a commanded velocity based on a jerk value which exceeds a predetermined jerk limit in response to the rapid changes in the desired velocity. A method of controlling a continuously variable transmission is also disclosed.

Abstract: In a shift control method, when a speed ratio of an automatic transmission is shifted from a third speed ratio to a first speed ratio before stoppage of a vehicle, a down shift line 3-1 in a shift pattern is shifted to a high-speed side to initiate shifting under a power-OFF condition. A third brake is released by setting the duty ratio of an electromagnetic valve of the third brake at 0% to establish a free condition (neutral condition) in an output shaft of a second transmission. While the duty ratio of an electromagnetic valve of a second clutch in a first transmission mechanism is set at 0%, the duty ratio of an electromagnetic valve of a second brake is gradually increased, so that the shifting from the second clutch to the second brake is made, and the first transmission mechanism is operatively shifted from the third speed ratio to a speed ratio corresponding to the first speed ratio.

Abstract: The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Abstract: The invention relates to a hydrostatic travelling drive for a vehicle, having a primary-adjustable and secondary-adjustable hydrostatic driving gear, which comprises at least two hydraulic machines in the form of a hydraulic pump drivable by a drive motor of the vehicle and a hydraulic motor connected to the hydraulic pump by way of at least one operating line, both of which can be adjusted in their respective stroke volume in dependence upon a control signal changing with the load of the driving gear. To avoid disturbances of the secondary adjustment of the hydrostatic driving gear through momentarily or rapidly occurring fluctuations of the driving-gear load, as control signal for adjusting the hydraulic motor a travelling-speed signal generated by a sensor device and corresponding with the travelling speed of the vehicle is used which with increasing travelling speed effects a swinging-back of the hydraulic motor, i.e. an adjustment in the direction of its minimum stroke volume.

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: A downstream rate limiting control is provided for controlling a continuously variable transmission. The rate limiting control monitors a input and a current machine state and computes the difference between these two inputs and compares the computed error to a predefined rate table to determine if the computed error should be limited or modified. The rate signal will modify the computed error within the control logic with respect to operator comfort and machine parameters.

Abstract: A control system for a multiple ratio transmission including a hydrokinetic torque converter with a pressure actuated friction bypass clutch, pressure actuated clutches and brakes controlling ratio changes in forward drive and for effecting reverse drive, a solenoid operated pressure control that develops an optimum clutch and brake pressure for smooth engagement and for increased torque capacity during start-up, and separate solenoid regulator valves for ratio shift valve control and for bypass clutch pressure control.

Abstract: An integrated power transmitting system includes a hydrostatic transmission and a mechanical transmission both being driven by an engine. The output of the hydrostatic transmission and the mechanical transmission are both selectively coupled to a work system through a final output shaft. A sensing arrangement senses the transmission input speed, the output of the hydrostatic transmission and the speed of the final output shaft and delivers the signals to the microprocessor. The microprocessor processes the received signals on a continuous basis and delivers a first set of command signals to control operation of the hydrostatic transmission and a second set of control signals to selectively control forward and reverse direction and high and low clutches within the mechanical transmission. A planetary arrangement within the mechanical transmission sums the speed of the hydrostatic transmission with a full range forward and reverse gear mechanism.

Abstract: A control system in which a judgment is made such that (i) a vehicle is in a forward drive control state, on condition that the forward/reverse drive lever is placed in the forward drive position and the actual speed ratio exceeds a specified small value in a forward drive direction, (ii) the vehicle is in a reverse drive control state on condition that the lever is placed in the reverse drive position and the actual speed ratio exceeds a specified small value in a reverse drive direction, (iii) the vehicle is in an engine brake control state, on condition that the lever is placed in the neutral position and the actual speed ratio exceeds the specified small value in the forward or reverse drive direction, (iv) the vehicle is in an FR shift control state, on condition that the lever is placed in the forward or reverse drive position and the actual speed ratio exceeds the specified small value in the reverse or forward drive direction, and (v) the vehicle is in a neutral control state, on condition that the le

Abstract: A speed change gear control system, wherein gear shift control for shifting the transmission from an arbitrary speed range into a higher speed range which provides higher absolute speed than the arbitrary speed range is performed, provided that the actual speed ratio e of the transmission satisfies .vertline.E.sub.1 .vertline.<.vertline.e.vertline.<.vertline.E.sub.0 .vertline. where E.sub.0 is a speed ratio for a shifting point at which the transmission is shifted from the arbitrary speed range into the higher speed range; and E.sub.1 is a specified speed ratio, or provided that .vertline.e.vertline.+(.DELTA.e/.DELTA.t).times.T.sub.1 >.vertline.E.sub.0 .vertline.-.DELTA.E.sub.1 where .DELTA.e is an increase in the speed ratio e over a period of time .DELTA.t; T.sub.1 is the filling time required for supplying hydraulic oil to a clutch which shifts the transmission from the arbitrary speed range to the higher speed range; and .DELTA.E.sub.1 is a specified small speed ratio.

Abstract: A control method/system for controlling engagement of a target gear ratio (GR.sub.T)in a vehicular automated mechanical transmission system (10) is provided. The control causes engine speed (ES) to be alternately greater than and then less than synchronous engine speed (ES=IS=OS*GR.sub.T) to cause torque reversals across the engaging positive jaw clutch associated with the target gear ratio to minimize or prevent partial engagement caused by torque lock conditions.

Abstract: In a transmission unit (1) for arrangement between a drive motor (47) and a consuming device (48), including a hydrostatic transmission (2), adjustable by means of an adjusting device (15a, 15b), a mechanical shift transmission (4), functionally arranged downstream of the hydrostatic transmission, having a plurality of gears (5, 6), and a control device for adjusting the hydrostatic transmission (2) by means of the adjusting device (15a, 15b) for a shifting process.The shift transmission (4) is a synchronous transmission with synchronization devices (7) for the gears (5, 6), includinga device (U, V2) for the measuring or monitoring of the output drive torque (M) of the hydrostatic transmission (2) is associated with the control device (16).

Abstract: A transmission for a heavy construction equipment such as a wheel type excavator adopting the hydrostatic drive system for transmitting travelling power. The transmission applied to a heavy construction equipment having an upper turning body, a lower travelling body and a turning joint for coupling the upper turning body to the lower travelling body so as to turn the upper turning body with respect to the lower travelling body and having a gear box disposed in the lower travelling body and provided with clutches for at least two speed change stages, and a control unit disposed in the upper turning body, a charging pump disposed in the upper turning body, a power shift motor disposed in the lower travelling body and adapted to be actuated by an oil fed from the charging pump, and a power shift pump disposed in the lower travelling body and adapted to be actuated by the power shift motor, with the gear box performing a speed change operation by oil fed from the power shift pump.

Abstract: A continuously variable transmission on a motor vehicle is controlled to control a speed reduction ratio using, as a control value, a rate of change di/dt of the speed reduction ratio that is determined using a reserve horsepower of an engine on the motor vehicle, an engine rotational speed Ne, a vehicle speed V of the motor vehicle, a present acceleration Ga of the motor vehicle, and a target acceleration Gon. A control process detects whether a rate of change of an indication by a driver of the motor vehicle of an intention to accelerate or decelerate the motor vehicle is greater than a predetermined value or not, whether a target engine rotational speed Neo corresponding to the indication is greater than an actual engine rotational speed Nea or not and whether the target acceleration Gon is greater than the present acceleration Ga on an acceleration side (positive side) or not.