A milling machine includes a rotor drive transmission having a plurality of gears disposed between a prime mover and a cutting rotor. The rotor drive transmission is associated with a rotor transmission hydraulic circuit including a hydraulic gearshift actuator to engage the plurality of gears in one or more gear ratios and a gearshift directional control valve to direct hydraulic fluid to and from the hydraulic gearshift actuator. In occurrence of a fault condition, the rotor transmission hydraulic circuit includes a gearshift trapping valve to maintain hydraulic pressure in the hydraulic gear actuator and the engaged gear ratio of the rotor drive transmission.

A milling machine includes a rotor drive transmission having a plurality of gears disposed between a prime mover and a cutting rotor. The rotor drive transmission is associated with a rotor transmission hydraulic circuit including a hydraulic gearshift actuator to engage the plurality of gears in one or more gear ratios and a gearshift directional control valve to direct hydraulic fluid to and from the hydraulic gearshift actuator. In occurrence of a fault condition, the rotor transmission hydraulic circuit includes a gearshift trapping valve to maintain hydraulic pressure in the hydraulic gear actuator and the engaged gear ratio of the rotor drive transmission.

A transmission includes a gearing arrangement configured to shift speed ratios by disengaging an off-going shift element and engaging an oncoming shift element and an electrohydraulic valve having an actuatable valve element configured to control an engagement state of the oncoming shift element. A controller is programmed to, during a shift of the transmission, in response to the off-going shift element disengaging and an expected ratio change not initiating, monotonically increase current to the valve to a maximum value to overcome frictional resistance on the valve element, and programmed to, in response to expiration of a timer and the ratio change still not initiating, send a repeating pattern of high and low current signals according to a duty cycle to overcome frictional resistance of the valve element.

A transmission includes a gearing arrangement configured to shift speed ratios by disengaging an off-going shift element and engaging an oncoming shift element and an electrohydraulic valve having an actuatable valve element configured to control an engagement state of the oncoming shift element. A controller is programmed to, during a shift of the transmission, in response to the off-going shift element disengaging and an expected ratio change not initiating, monotonically increase current to the valve to a maximum value to overcome frictional resistance on the valve element, and programmed to, in response to expiration of a timer and the ratio change still not initiating, send a repeating pattern of high and low current signals according to a duty cycle to overcome frictional resistance of the valve element.

A sensor arrangement detects an angle of an actuator which is rotationally arranged on a support. The arrangement includes a first sensor element and a second sensor element. The first sensor element can be coupled to the actuator in order carry out a movement with respect to the support in accordance with a rotation of the actuator. The second sensor element can be rotationally fixed on the support and can be coupled to the first sensor element in order to produce, when rotating the actuator and a thus resulting movement between the first sensor element and the second sensor element, a sensor signal which is dependent on the rotation carried out by the actuator.

A sensor arrangement detects an angle of an actuator which is rotationally arranged on a support. The arrangement includes a first sensor element and a second sensor element. The first sensor element can be coupled to the actuator in order carry out a movement with respect to the support in accordance with a rotation of the actuator. The second sensor element can be rotationally fixed on the support and can be coupled to the first sensor element in order to produce, when rotating the actuator and a thus resulting movement between the first sensor element and the second sensor element, a sensor signal which is dependent on the rotation carried out by the actuator.

The present invention addresses the problem of obtaining an electronic control device for a vehicular automatic transmission that suppresses sudden acceleration, sudden deceleration, and gear shift shock that occur when the transmission moves into a fail-safe mode due to the electronic control device stopping during a main CPU abnormality. An electronic control device 100 for a vehicular automatic transmission has: a main CPU 3 that performs gear shift control for the vehicular automatic transmission; and a sub-CPU 4 that detects abnormalities in the main CPU 3. When the sub-CPU 4 detects an abnormality in the main CPU 3 while the vehicle is traveling, the sub-CPU 4 stops the gear shift control executed by the main CPU 3. Next, when the control status of the vehicular automatic transmission is in a state of maintaining the gear position, the sub-PCU 4 continues the maintaining of the gear position; when the control status is in a state of changing the gear position, the sub-PCU 4 continues a gear shift operation for the gear position, and, instead of the main CPU 3, performs alternative control for maintaining the gear position after the gear position is changed. Subsequently, as a result of a stop in the traveling of the vehicle, the sub-PCU 4 finishes the alternative control and abnormally stops the electronic control of the automatic transmission.

The present invention addresses the problem of obtaining an electronic control device for a vehicular automatic transmission that suppresses sudden acceleration, sudden deceleration, and gear shift shock that occur when the transmission moves into a fail-safe mode due to the electronic control device stopping during a main CPU abnormality. An electronic control device 100 for a vehicular automatic transmission has: a main CPU 3 that performs gear shift control for the vehicular automatic transmission; and a sub-CPU 4 that detects abnormalities in the main CPU 3. When the sub-CPU 4 detects an abnormality in the main CPU 3 while the vehicle is traveling, the sub-CPU 4 stops the gear shift control executed by the main CPU 3. Next, when the control status of the vehicular automatic transmission is in a state of maintaining the gear position, the sub-PCU 4 continues the maintaining of the gear position; when the control status is in a state of changing the gear position, the sub-PCU 4 continues a gear shift operation for the gear position, and, instead of the main CPU 3, performs alternative control for maintaining the gear position after the gear position is changed. Subsequently, as a result of a stop in the traveling of the vehicle, the sub-PCU 4 finishes the alternative control and abnormally stops the electronic control of the automatic transmission.

A shift range control device switches a shift range by controlling driving of a motor. A learning unit learns, as a position correction value, a normal state time correction value calculated based on first and/or second reference angles when an output shaft signal is available when turning on of a start switch. The first reference angle is a motor angle when the output shaft signal changes in response to the rotation of the motor in a first direction. The second reference angle is the motor angle when the output shaft signal changes in response to the motor rotation in a second direction opposite to the first direction. A motor angle target value is set by using the normal state time correction value stored during a period from when all the output shaft signals are determined to be unavailable to when the start switch is turned off.

Desired is a control device for a vehicle drive apparatus capable of determining an engagement failure in an engagement device when shifting a transmission device to a neutral state and making the rotational speed of a driving force source reduced. In order to shift a transmission device from a state in which an object shift speed is established and the vehicle is traveling to a neutral state in which no shift speed is established in the transmission device (#02), when an object engagement device is disengaged while maintaining engagement of a non-object engagement device and the rotational speed of a driving force source (#04, #06) is made to be reduced, an engagement failure in the object engagement device (#02, #07) is determined based on a change in the rotational speed of an input member.