Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Yasushi Yamada

Masahide Iwazawa

Kiyotaka Iwata

Akira Itoh

Akihiro Ohno

Tsuyoshi Murakami

Ryouhei Shigeta

Akira Ito

Yutaka Mori

Yoshiyuki Shibata

Tomoaki Kato

Hisaaki Wakao

Yukihiko Kanayama

Fukami Imai

Isao Ito

Tadashi Yoshioka

Akio Maekawa

Susumu Koike

Shunzo Tanaka

In a control apparatus for a hydraulic power steering system including multiple electric pumps, a first ECU determines that start-up of a first motor is completed when a first current value, which is a value of current flowing to a first electric pump, has been within a prescribed current range continuously for a prescribed period of time or longer. An upper limit of the prescribed current range is set to be less than to a limit value provided as an upper limit of a current supplied simultaneously to the first and second electric pumps after completion of start-up. A lower limit of the prescribed current range is set to a minimum value of a current indicating that the first electric pump is in an energized state. After start-up of the first motor is determined to be completed, a second ECU starts electric power supply to the second electric pump.

Control apparatus for hydraulic power steering system

An IG-off-timer measures the time t_off from when an engine is stopped, or an ignition is turned off. An ECU sequentially memorizes an estimated temperature of each of heat generating portions as a memorized temperature. Immediately after the engine is re-started, the ECU sets an initial value of the estimated temperature of each heat generating portion in such a manner that the initial value reflects a temperature drop of the heat generating portion in the deactivation period of the engine. The temperature of the heat generating portion is thus accurately estimated even after re-starting of the engine. The heat generating portions are thus appropriately protected.

Drive force distribution device and method for distributing drive force

A control device is provided for electrically controlling a drive power transmission device arranged on a driving power transmission path of a front-and rear wheel drive vehicle thereby to switch the drive mode of the vehicle selectively to either of a two-wheel drive mode and a four-wheel drive mode. The control device inhibits the drive mode from being switched to that commanded to be switched to when the vehicle is traveling at a slower speed than a predetermined speed and when the rotational speed difference between front and rear wheels is larger than a predetermined value. Further, the control device gradually decreases a present torque which the driving power transmission device is transmitting before the switching of the drive mode, to a target torque which the drive power transmission device is to transmit after the switching of the drive mode, when the difference between the present and target torques is more than another predetermined valve at the time of the switching of the drive mode. Thus, the driving power transmission path can be prevented from generating the drive torque beyond a tolerable valve as well as making a noise due to the instantaneous switching of the drive mode during the traveling of the vehicle, and the vehicle can be prevented from abruptly changing its motion by the cause of the instantaneous drive mode switching.

Control device for front-and-rear wheel drive vehicle

A controller controls an electric motor to provide assist power corresponding to steering operation for an electric power steering apparatus. The controller comprises a detecting device, a filtering device, a judging device and a determining device. The detecting device detects present voltage of a power source for the electric motor. The filtering device filters the present voltage based on a small time-constant when the voltage of the power source increases and based on a large time-constant when the voltage of the power source decreases. The judging device judges whether the filtered voltage is lower than a predetermined threshold. And, the determining device determines being abnormality of the power source when it is judged that the filtered voltage is lower than the threshold.

Controller and control method for an electric power steering apparatus

A torque distribution control device for a four-wheel drive vehicle is disclosed, wherein a torque transmitted from an engine to prime drive wheels is distributed by an electromagnetic clutch to sub-drive wheels on an on-demand basis. A pre-torque is determined based on a vehicle speed and a throttle opening degree in a feed-forward sense. A compensation torque is determined based on the rotational speed difference between the prime drive wheels and the sub-drive wheels and the vehicle speed in a feedback sense. The pre-torque and the compensation torque are added for a command torque, depending on which the electromagnetic clutch is controlled to transmit the torque from the engine to the sub-drive wheels. At this time, since the command torque is limited to an upper limit value therefor or below in dependence on the engine torque, an ECU can be prevented from applying an excess current to an electromagnetic coil of the electromagnetic clutch and hence, from generating heat to raise its temperature when the engine torque is small.

Torque distribution control device for four-wheel drive vehicle

A four-wheel drive vehicle is provided with a drive power transmission device for controlling the connection degree of a front wheel axle driven by an engine with a rear wheel axle. A drive power distribution control device is responsive to a vehicle speed, a rotational difference between front wheels driven by the front wheel axle and rear wheels driven by the rear wheel axle, a throttle opening degree signal and the like and controls the drive power transmission device. The drive power distribution control device judges whether the vehicle is beginning to start or not and at the starting of the vehicle, controls the transmission rate of the drive power transmission device in dependence on the state or manner in which the vehicle is beginning to start.

Drive power distribution control method and device for four-wheel drive vehicle

A steering apparatus controller for an electric power steering apparatus, which includes an electric motor for generating assist torque for assisting steering of a steering wheel and the steering apparatus controller is designed to execute a feedback control of the applied drive voltage to the electric motor based on the detection result of the actual current that flows through the motor. A sensor detects the actual current to produce the detection result. When detecting an abnormal decrease of the drive voltage of the sensor, a voltage controller maintains the applied voltage to the electric motor at the voltage at a predetermined time before the drive voltage abnormally decreased.

Steering apparatus controller for electric power steering apparatus

A control apparatus of an electric power steering system has first to fourth calculators and an abnormality detector. The first calculator calculates an assist current command value, which corresponds to assist force for reducing steering force of the steering wheel, based on the steering torque of the steering wheel. The second to fourth calculators calculate a compensation current command value, which corresponds to compensation force for compensating for movement of the steering wheel, based on the angular velocity of the steering wheel that has been estimated based on the terminal-to-terminal voltage of the motor. The abnormality detector detects an abnormality of the terminal voltages of the motor. When the abnormality detector detects an abnormality, the second to fourth calculators substitute zero for the steering wheel angular velocity and then calculates the compensation current command value.

Apparatus and method for controlling electric power steering system

A control apparatus of an electric power steering system has calculating means, controlling means, determining means suppressing means, canceling means. Calculating means calculates an assist current value that corresponds to the assist force based on steering torque of a steering wheel. Controlling means executes assist control of the motor based on the assist current value. Determining means determines an abnormality in the circuit. Suppressing means suppresses the assist control when an abnormality in the circuit is determined. If the determination of an abnormality has continued longer than a predetermined time since the suppression of the assist control, the suppressing means opens relay means that permits electric power to be supplied to the motor. When it is determined that the circuit returns to normal with the assist control suppressed, the canceling means cancels the suppression of the assist control.

Control apparatus of electric power steering

A temperature sensing apparatus comprises a temperature sensor, a current measuring device and temperature detection circuit. The temperature sensor contains a thermal resistor that is disposed near a motor and outputs voltages acting to the thermal resistor. The current measuring device measures quantity of current that is applied to the motor. The temperature detection circuit detects temperature of the motor according to the output voltages from the temperature sensor. And, the temperature detection circuit judges whether a predetermined quantity of current is applied to the motor during a predetermined time. When the predetermined quantity of current is applied to the motor during the predetermined time, the temperature detection circuit compares a temperature detected by the current measuring device with a predetermined temperature. When the detected temperature is lower than the predetermined temperature, the temperature detection circuit decides a wire of the thermal resistor breaks.

Growing community of inventors

Kariya, Japan

Yasushi Yamada