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.

Disclosed is a method of diagnosing a malfunction in a dual clutch transmission (DCT) attributable to a gear synchromesh failure, without an output shaft speed sensor. The method includes: calculating, a difference (referred to as a first difference) between a first input shaft speed and the product of a wheel speed and a first gear ratio; a difference (referred to as a second difference) between a second input shaft speed and the product of a wheel speed and a second gear ratio; diagnosing a first input shaft as having a transmission gear synchromesh failure when the first difference is greater than a first reference value and the second difference is equal to or smaller than a second reference value; and performing control such that a gear shifting operation is performed using only a second input shaft when the first input shaft is diagnosed as having a transmission gear synchromesh failure.

A continuously variable transmission includes a primary pulley, a secondary pulley, a metal belt and a controller. The metal ring includes a ring and a plurality of elements bundled by the ring. The elements have respective receiving portions opening in a radial direction of the metal belt and receive the ring in the receiving portions. Assuming a direction perpendicular to a circumferential direction and a radial direction of the metal belt as a lateral direction L, the controller executes a falling-off countermeasure control of the element when a relative movement of the element in the lateral direction L with respect to the ring is detected or a presence of an action of a force on the element which causes such relative movement is detected.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

An apparatus for diagnosing an automatic transmission for detecting abnormality during driving of a vehicle includes a G-sensor configured to measure a vibration signal including a longitudinal vibration signal, a status detection unit configured to obtain the vibration signal of the G-sensor and status data of transmission and engine sensors of the vehicle, and a controller configured to check an operational element for each shifting operation by using a current shift-stage, a target shift-stage, and a shifting time detected as the status data, measure the longitudinal vibration signal of the G-sensor to calculate fluctuation level of the longitudinal vibration signal for each operational element, and determine a shift shock event when a longitudinal vibration signal value after adjustment based on driving acceleration of the vehicle exceeds a reference value.

In a conical friction ring transmission, the safety device may have a normal state, in which electrical energy is applied to the safety device, and a failure state, in which the safety device is free of electrical energy, or a bi-stable safety actuator with a normal position and a failure position, and may change the effect parameter of a mechanical articulating element for adjusting a friction ring. An especially compact design of the conical friction ring transmission is thus achieved.

A controlling apparatus for an electric shift-by-wire system is disclosed. The apparatus includes a shift stage sensor detecting information on a target shift stage according to the operation of the shift lever; a position sensor detecting information on a position of the motor; and a controller configured to receive the detected information from the shift stage sensor and the position sensor, when the target shift stage is a P stage, determine whether the P stage is likely to be released using the position information of the motor, and when it is determined that the P stage is likely to be released, limit rotation of the motor.

A continuously variable transmission includes a primary pulley, a secondary pulley, a metal belt and a controller. The metal ring includes a ring and a plurality of elements bundled by the ring. The elements have respective receiving portions opening in a radial direction of the metal belt and receive the ring in the receiving portions. Assuming a direction perpendicular to a circumferential direction and a radial direction of the metal belt as a lateral direction L, the controller executes a falling-off countermeasure control of the element when a relative movement of the element in the lateral direction L with respect to the ring is detected or a presence of an action of a force on the element which causes such relative movement is detected.

The transmission controller is configured to, when the received range position signal indicates that the range position is switched from a travelling range to a neutral range during travelling, output an instruction to disengage all of friction elements that are in an engaged state in the travelling range, output an instruction to at least one friction element before the instruction to disengage all of the friction elements that are in the engaged state in the travelling range is output, confirm a change in a rotation speed of a transmission input shaft after the instruction to disengage is output to the at least one friction element, and when there is no change in the rotation speed, diagnose that the friction element instructed to be disengaged is in an erroneously engaged state in which the friction element is not able to be disengaged.

The transmission controller is configured to, when the received range position signal indicates that the range position is switched from a travelling range to a neutral range during travelling, output an instruction to disengage all of friction elements that are in an engaged state in the travelling range, output an instruction to at least one friction element before the instruction to disengage all of the friction elements that are in the engaged state in the travelling range is output, confirm a change in a rotation speed of a transmission input shaft after the instruction to disengage is output to the at least one friction element, and when there is no change in the rotation speed, diagnose that the friction element instructed to be disengaged is in an erroneously engaged state in which the friction element is not able to be disengaged.