A working fluid supply system is provided with: a first oil pump and a second oil pump driven by an engine; a switching valve configured to cause a discharge passage of the second oil pump to communicate with at least one of a supply passage and a first drain passage; and a controller configured to switch the switching valve. The controller is configured to switch the switching valve by spending a switching time that is set in accordance with a degree of pressure variation predicted to be caused in the supply passage when the switching valve is switched instantaneously.

Methods and systems for a hydromechanical transmission are provided herein. In one example, the transmission operating method includes asynchronously shifting between a first pair of drive ranges in the transmission via operation of two clutches and a variable displacement hydraulic pump in a hydrostatic assembly. In the method, asynchronously shifting between the two drive ranges includes a plurality of phases that include a swiveling phase where a speed of the hydrostatic assembly is inverted.

Methods and systems for a hydromechanical transmission are provided herein. In one example, the transmission operating method includes asynchronously shifting between a first pair of drive ranges in the transmission via operation of two clutches and a variable displacement hydraulic pump in a hydrostatic assembly. In the method, asynchronously shifting between the two drive ranges includes a plurality of phases that include a swiveling phase where a speed of the hydrostatic assembly is inverted.

An apparatus for controlling a transmission of a vehicle includes a processor configured to identify a location of a speed bump based on collected information about a specified section of a front road and determine whether the vehicle enters a section of the speed bump, and to set an oil pressure of the transmission to a first oil pressure in a normal driving section and set the oil pressure of the transmission to a second oil pressure when the vehicle enters the section of the speed bump, and a controller that controls the oil pressure of the transmission corresponding to a setting of the processor for each driving section of the vehicle.

A vehicle failure-factor specifying apparatus includes (a) a peculiarity-presence determining portion configured to determine, based on a pre-failure driving state in a stage prior to occurrence of a certain failure in a vehicle, whether a peculiarity was present or absent in the pre-failure driving state, and (b) a failure-causing-driving state specifying portion configured, when the peculiarity was present in the pre-failure driving state, to determine whether the peculiarity present in the pre-failure driving state of the vehicle is substantially identical with a peculiarity in the pre-failure driving state of other vehicles. The peculiarity-presence determining portion determines whether the peculiarity was present or absent in the pre-failure driving state of the vehicle, depending on whether a frequency distribution of the pre-failure driving state of the vehicle is deviated from a frequency distribution of a non-failure driving state of a plurality of vehicles including the other vehicles in a non-failure case.

A tidal current energy converter including an infinitely variable transmission (IVT) control system and a hybrid vertical axis wind (or water) turbine (VAWTs) apparatus. The hybrid VAWT apparatus includes a modified-Savonius (MS) rotor in the central region and a straight bladed H-type Darrieus rotor in the surrounding annular region. The IVT control system includes a nonlinear closed-loop control combined with an integral time-delay feedback control to adjust a speed ratio of the IVT. A speed ratio control for an IVT system involves a forward speed controller and/or a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.

A continuous variable transmission (CVT) hydraulic pressure control device includes: a pressure regulation valve regulating an operation pressure of oil supplied to a friction element of a forward-rearward device; and a switch valve to respectively switch oil discharge paths through which the oil supplied to the friction element is discharged, respectively by a pilot pressure from the pressure regulation valve and an elastic force of a return spring. In particular, the oil discharge paths switched by the switch valve have oil flow resistances different from each other.

A control system for a vehicle uses one or more inputs of a velocity request, a brake request, a speed request, travel direction indication, engine speed, and vehicle speed to determine a control strategy for a continuously variable transmission. A target engine speed is selected based upon the inputs, and the engine and continuously variable transmission ratio are controlled to achieve the target engine speed while controlling the vehicle according to the inputs. In some embodiments, the control strategy further selects the target engine speed according to accessory system demands, such as a hoist or lift system.

A control system for a vehicle uses one or more inputs of a velocity request, a brake request, a speed request, travel direction indication, engine speed, and vehicle speed to determine a control strategy for a continuously variable transmission. A target engine speed is selected based upon the inputs, and the engine and continuously variable transmission ratio are controlled to achieve the target engine speed while controlling the vehicle according to the inputs. In some embodiments, the control strategy further selects the target engine speed according to accessory system demands, such as a hoist or lift system.

A working vehicle of this invention includes a main speed change structure that includes a continuously variable speed change structure such as an HMT structure and a multi-speed speed change structure capable of switching between a first power transmission state with a first gear ratio and a second power transmission state with a second gear ratio providing a higher speed than the first gear ratio. A control device causes the continuously variable speed change structure to be accelerated to a forward travel side in accordance with an accelerating operation of a speed change operation member in a forward travel direction, and causes the multi-speed speed change structure to be changed from a first power transmission state to a second power transmission state when the rotational speed of the speed change output shaft reaches a switching speed set to exceed a work speed range.