There is provided a vehicle engine control system that includes engine and transmission control functions and enables evacuation driving to be readily performed. A monitoring control circuit unit and an error processing circuit unit monitors controlling operation of a main control circuit unit; when the occurrence frequency of valve-opening control abnormality becomes larger than threshold value, a first storage circuit stores the occurrence frequency, and driving of an intake valve control motor is stopped to set to fixed opening degree; when transmission-control abnormality is occurs, power supply to automatic transmission is stopped to set to the third speed fixation ratio; when an abnormality occurs, evacuation driving is implemented using fixed opening degree and automatic transmission ratio, variable rotation speed and fixed transmission ratio, or fixed opening degree and fixed transmission ratio. When valve-opening control abnormality or transmission-control abnormality occurs, fuel injection control is prevented from being inappropriately stopped.

A prime mover control device of a work vehicle equipped with a torque converter includes: a speed ratio calculation unit that calculates a speed ratio of the torque converter; and a rotational speed limit unit that, when a speed ratio falls within a preset speed ratio range, limits a maximum rotational speed of the prime mover to be lower as compared with a maximum rotational speed set when a speed ratio falls without the preset speed ratio range. When a state in which the speed ratio calculated by the speed ratio calculation unit falls within the preset speed ratio range is maintained for a predetermined time period, the rotational speed limit unit changes a maximum rotational speed of the prime mover to a higher maximum rotational speed than the limited maximum rotational speed limited to be lower by the rotational speed limit unit.

A power transmission includes first and second clutches for switching a transmission path for a driving force. A work vehicle includes a clutch controlling unit and an engine controlling unit. The clutch controlling unit is configured to determine which of first and second modes the transmission path is switched into based on which of a range of greater than or equal to a mode switching threshold and a range of less than or equal to the mode switching threshold a speed ratio parameter falls into, and is configured to output a clutch command signal causing one of the first and second clutches to be engaged corresponding to the determined mode. The engine controlling unit is configured to apply an offset to a rotational speed of an input shaft such that after switching into the determined mode, the speed ratio parameter deviates from the mode switching threshold in the switched mode.

A vehicle drive control device in a vehicle including an engine comprising a throttle valve and a supercharger with an air bypass valve changed from a closing side to an opening side when a closing speed of the throttle valve is higher than a speed determination value, the vehicle drive control device providing a torque-down control of the engine by operating the throttle valve to a closing side, wherein at the time of provision of the torque-down control of the engine in which the throttle valve is operated to the closing side when a rotation speed of the engine is equal to or greater than a predetermined rotation speed and a speed ratio of a torque converter is equal to or less than a predetermined value in a supercharged state, the throttle valve is caused to perform a closing operation at the closing speed lower than the speed determination value.

A vehicle control device is configured to execute a fuel cut control for stopping fuel supply to an internal combustion engine in response to a deceleration request to a vehicle; disengage a lock-up clutch and open a throttle of the vehicle during execution of fuel cut control; execute motor assist in a case where there is an acceleration request to a vehicle while the lock-up clutch is disengaged and the throttle is opened; and execute a motor torque reduction control for temporarily reducing an output from an electric motor based on a rotation speed of the internal combustion engine and a rotation speed of a main shaft during the execution of the motor assist.

An engine-driven working machine including a controller by which a time period until the rotation speed limitation mode is canceled can be shortened. After a throttle valve is moved to a fully-closed position by an operation to allow the engine to finish the fast idling state and while the engine is transited to an idling state, the controller cancels the rotation speed limitation mode by detecting an event in which a cycle period of rotation speed variations of the engine is longer than a cycle period of rotation speed variation in the fast idling state.

Disclosed is a fuel injection control system for a single-cylinder diesel engine, comprising: a set of operating condition sensors including an accelerator pedal position sensor and a cooling water temperature sensor, an input signal interface capable of receiving an input signal from the operating condition sensors, a control unit connected to the input signal interface, and a rotational speed sensor provided at a camshaft or starting shaft of the single-cylinder diesel engine. The rational speed sensor is connected to the control unit via a rotational speed correction circuit. The control system can easily and quickly determine the rotational speed and operating stroke of the single-cylinder diesel engine, so as to quickly determine the fuel injection quantity and injection timing of the single-cylinder diesel engine in real time.

A method to control a road vehicle during a slip of the drive wheels and having the steps of: detecting a slip of at least one drive wheel; and controlling, only during a slip of at least one drive wheel, a driving unit of the road vehicle with a signalling law so as to obtain a cyclic operating irregularity, which generates an abnormal vibration and/or an abnormal noise.

A vehicle control device includes a storage device and a processor. The storage device is configured to store relationship prescription data that prescribe a relationship between a state of a vehicle and an action variable that is a variable related to an operation of an electronic device in the vehicle. The processor is configured to calculate a reward corresponding to the operation of the electronic device. The processor is configured to update the relationship prescription data using, as inputs to updated mapping determined in advance, the state of the vehicle that is based on a detection value that is acquired, a value of the action variable that is used to operate the electronic device, and the reward corresponding to the operation of the electronic device when a computation load on the processor is equal to or less than a predetermined load.

Methods and systems are presented for assessing the presence or absence of engine torque deviation which may indicate air-fuel ratio imbalance between engine cylinders. In one example, the method may include assessing the presence or absence of engine torque variation based on engine torque deviation from a desired engine torque during a deceleration fuel shut-off event.