A control device provided in a gear shifting device includes an electronic control unit. The electronic control unit determines whether an abnormality of the gear shifting device has occurred, performs a fail-safe process of switching the frictional engagement element corresponding to an abnormality to a disengaged state and fixing the gear shift ratio of the gear shifting device when it is determined that an abnormality has occurred, determines whether the abnormality has been relieved based on a behavior of an input signal at the time of operating a drive device of the frictional engagement element corresponding to an abnormality on condition that the frictional engagement element is maintained in the disengaged state after it is determined that the abnormality has occurred, and releases the fail-safe process when it is determined that the abnormality has been relieved.

A control device provided in a gear shifting device includes an electronic control unit. The electronic control unit determines whether an abnormality of the gear shifting device has occurred, performs a fail-safe process of switching the frictional engagement element corresponding to an abnormality to a disengaged state and fixing the gear shift ratio of the gear shifting device when it is determined that an abnormality has occurred, determines whether the abnormality has been relieved based on a behavior of an input signal at the time of operating a drive device of the frictional engagement element corresponding to an abnormality on condition that the frictional engagement element is maintained in the disengaged state after it is determined that the abnormality has occurred, and releases the fail-safe process when it is determined that the abnormality has been relieved.

A continuously variable transmission includes a primary pulley, a secondary pulley, a metal belt wound around the primary pulley and the secondary pulley, and a controller. The metal belt includes a ring and a plurality of elements. The elements have respective receiving portions opening in a radial direction of the belt and receive the ring in the receiving portions. The controller executes a preliminary determined falling-off countermeasure control of the element when the end play larger than the predetermined length is detected to be generated or the continuously variable transmission is detected to be under the operation condition in which the end plays concentrate.

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.

A vehicle anomaly analysis apparatus for analyzing an anomaly having occurred in a shift control operation executed in an automatic transmission of a vehicle, by using a rotational speed changed in process of the shift control operation. The vehicle anomaly analysis apparatus specifies cause of the anomaly in the shift control operation, by applying an anomaly-cause specifying model that indicates a relationship between a manner of chronological change of a racing amount and the cause of the anomaly in the shift control operation, to the manner of the chronological change of the racing amount upon occurrence of the anomaly in the shift control operation. The racing amount is an amount of increase of the rotational speed in the process of the shift control operation, relative to a reference rotational speed that is based on a gear ratio and an output rotational speed of the automatic transmission.

Methods and systems are provided for controlling and diagnosing one or more clutches in a transmission. In one example, a method for operation of a vehicle system is provided that includes at a diagnostic controller or processing unit independent from a driveline controller or processing unit, respectively, determining an engagement state of a clutch in a transmission of the vehicle system, wherein the engagement state is selected from a group of three or more clutch engagement states. The method further includes identifying an unauthorized clutch state based on the engagement state of the clutch and a speed of the vehicle and responsive to the identification of the unauthorized clutch state, operating the vehicle system in a fault state.

A transmission system for a vehicle comprises a first partial transmission (T1) with a first controllable clutch (C1) and a second partial transmission (T2) with a second controllable clutch (C2) each forming a respective transmission path between an input (ci; ci1, ci2) and a common output (to), the first and the second controllable clutch (C1, C2) having a first and a second actuating means (CA1,CA2) respectively, to control an operational state of said controllable clutches. A controller (CNTR) is provided to control the first and the second actuating means, the controller being configured to selectively assume one of a plurality of control modes. These include amongst others a safety control mode which is selected upon detecting that a value of an acceleration of the vehicle is lower than a negative threshold value.

A method for calculating a degradation degree of a damper clutch of an automatic transmission of a vehicle includes: filtering, by a controller, a vibration signal of the vehicle according to driving of the vehicle in order to remove a vibration signal of the vehicle corresponding to a natural frequency of an engine of the vehicle from the vibration signal of the vehicle according to the driving of the vehicle; converting, by the controller, the filtered vibration signal into a signal including a sinusoidal wave having a natural frequency of the automatic transmission based on a gear stage of the automatic transmission of the vehicle by using a frequency analysis method; and calculating, by the controller, a degradation degree of the damper clutch included in a torque converter of the automatic transmission based on a magnitude of the sinusoidal wave having the natural frequency of the automatic transmission.

An alternative braking apparatus for a vehicle includes a gear type automatic transmission having at least one clutch and at least one brake for changing the meshing state of gears, and a control unit configured to switch the shift stage of the automatic transmission by controlling the clutch and the brake. The control unit is configured to perform alternative braking that controls the clutch and the brake so that an output shaft of the automatic transmission is braked by a braking force of the brake through the gears when the control unit determines that a braking device of the vehicle cannot normally apply braking forces to wheels despite that the vehicle needs to be braked.

Methods and systems are provided for controlling and diagnosing a mechanical vehicle component. In one example, a method may include determining an input device state and an electric machine torque at a diagnostic controller, and identifying a fault condition based on these determinations. Further, the diagnostic controller may trigger an active fault state of the mechanical vehicle component to avoid unintended vehicle acceleration, particularly at low speeds.