Electrically controllable hydraulic system for a vehicle transmission and method for controlling the same An electrically controllable hydraulic system (1) for a vehicle transmission comprises a pressure pump system (4a, 4b) and a subsystem (1A) comprising a transmission element (2) and an electrically controlled hydraulic pressure controlling module (1B) including a hydraulic valve element (15) for controlling a hydraulic pressure for actuating the transmission element (2) and an electromagnetically controllable operating element (21) for operating the hydraulic valve element (15). The subsystem (1A) and the pressure controlling module (1B) have a first and a second cut-off frequency (f1, f2) with f2>f1. The hydraulic system includes a driver circuit (32) for driving the pressure controlling module (1B) that comprises a full bridge circuit and a control circuit (42) for simultaneously controlling both switching elements of the driver circuit with a duty cycle according to an input value of the input signal (Iset) dithered with a frequency (f.sub.dith) in the range (f1, f2).

A hydraulic pressure supply system includes a mechanical oil pump, an electric oil pump, a first flow path, a second flow path, and a cut-off mechanism. The mechanical oil pump is configured to operate by power from an engine. The electric oil pump is configured to operate by power from a motor. In the first flow path, oil supplied from the mechanical oil pump and the electric oil pump flows, the first flow path being coupled to the mechanical oil pump and the electric oil pump. The second flow path branches off from the first flow path and is configured to cause an oil to return to an oil pan via a torque converter. The cut-off mechanism is configured to close off the second flow path by oil delivered from the electric oil pump.

A current control device brings, after a target current has been changed to an upper side, a solenoid into a full-on state at a first timing that arrives in a predetermined control transition cycle shorter than an on-off cycle, determines whether an excitation current has become equal to or larger than a full-on threshold larger than the target current, brings the solenoid into a full-off state at a first timing that arrives in a predetermined energization switching cycle shorter than the on-off cycle after the excitation current has become equal to or larger than the full-on threshold, determines whether the excitation current has become equal to or smaller than a full-off threshold smaller than the target current, and causes a transition to a steady control at a first timing that arrives in the control transition cycle after the excitation current has become equal to or smaller than the full-off threshold.

An automatic transmission controller includes a solenoid drive controller that performs a current feedback control to one or more of a plurality of solenoids that correspond to a plurality of gear positions for shifting to one of the plurality of gear positions in a transmission mechanism. From among all the solenoids, the solenoid drive controller distinguishes one or more target solenoids to operate to shift from a current gear position to a post-change gear position, and changes a current feedback cycle of the target solenoid(s) for performing the current feedback control.

A drive device includes: a first current path that has a high-side MOSFET; a second current path that has a low-side MOSFET; and a third current path connected to the other end portion of a coil and positioned between the first current path and the second current path. The drive device further includes: PWM drive circuits that generate a drive signal through PWM control; and an overcurrent detection circuit that detects that an overcurrent has flowed through the current paths. It is possible to precisely detect the occurrence of a battery short circuit and a ground short circuit by detecting which of the first current path and the second current path an overcurrent has flowed through.

A control apparatus for controlling a linear solenoid by controlling a driving current supplied to the linear solenoid through a feedback control. The feedback control is executed by a feedback control system having parameters that are determined in accordance with an ILQ design method. In a frequency characteristic of a gain of a transfer function representing a ratio of an output to a disturbance in the feedback control system, the gain is lower than 0[dB] throughout all frequency ranges.

A circuit and a method of controlling a circuit is provided for an electronic control of an electromagnetic drive of an electromagnetic valve. The circuit provides a control signal for the electromagnetic drive which has a high level and a low level. The control signal comprises at least a first time interval having a first duty cycle, an optional second time interval having a second duty cycle, and a third time interval having a third duty cycle, the first, second and third duty cycles being less than one. The first duty cycle is greater than the second duty cycle and the second duty cycle is greater than the third duty cycle. The time length of the time intervals and the size of the duty cycles are configured such that the electromagnetic drive changes from a first operating state to a second operating state in the first time interval, optionally remains in the second operating state in the second time interval, and changes from the second operating state to the first operating state in the third time interval.

A control device that includes an electronic control unit that is configured to: detect an actual current value flowing through the solenoid valve; receive a current command value and the actual current value detected and generate a primary command voltage value while feeding back the current command value on the basis of the actual current value; calculate a dither command voltage value to cause a periodic voltage oscillation; filter the actual current value detected to remove a frequency corresponding to a period of the dither command voltage value and output the filtered actual current value; generate a secondary command voltage value by superimposing the dither command voltage value generated on the primary command voltage value generated; convert the secondary command voltage value generated into a PWM signal; and generate, on the basis of the PWM signal generated, an application voltage to be applied to the solenoid valve.

A current controller in an automatic transmission controller shifts to a gear position from among a plurality of gear positions of a transmission mechanism by performing a current control for supplying an electric current to at least one of a plurality of solenoids corresponding to the plurality of gear positions. When the gear position is currently shifted or is going to be shifted from a pre-change gear position to a post-change gear position, the current controller distinguishes a target solenoid to operate from a non-target solenoid for shifting to the post-change gear position. The current controller performs the current control for the non-target solenoid using a control method having a lighter processing load than the processing load of the current control method for the target solenoid.

An electromagnetic valve control device includes a control signal generator to, through feedback control involving an environmental coefficient, generate a control signal intended for at least one electromagnetic valve and corresponding to a target electric current value, a coefficient determiner to determine an environmental coefficient during a learning period from a start of a driver operation to an end of a predetermined time, and an operation limiter to limit respective operations of the at least one electromagnetic valve and a gear transmission during the learning period.