Honda Giken Kogyo Kabushiki Kaisha

501 Nec Home Electronics

Tetsuji Muto

Makoto Sato

Shohei Matsuda

Shuji Shiraishi

Tetsuro Hamada

Toshio Yahagi

Katsuhiko Masuda

Kazunori Shibuya

Kazuhiko Shimada

Yoshihiro Iwagawa

Hiroshi Ikegami

Tadashi Nose

Satoshi Baba

Yuji Fujimura

In a multi-axle drive vehicle having a first axle which is directly coupled to a power source, and a second axle which is coupled to the power source by way of a coupling such as a viscous coupling which is adapted to transmit torque as a mathematical function of a difference in rotational speed between its input end and output end, to the end of eliminating the problems arising from transmission of braking force between the wheels of difference axles, the vehicle is further provided with a clutch for selectively interrupting transmission of power from the power source to the second axle, a brake sensor for detecting activation of a brake system of the vehicle, and a control unit for activating the clutch when the brake sensor has detected activation of the brake system. The conditions for activating the clutch may further include that the vehicle is running at a high speed which may be detected either directly or from a shift position of the power transmission system of the vehicle.

Four wheel drive vehicle

A control system for controlling the slip of a driving wheel of a vehicle senses the speed of at least a driving wheel and the vehicle speed. A slip rate calculator and a differentiator calculate the slip rate and the differential of the slip rate, respectively. An excessive slip rate circuit, a prediction control circuit, and an excessive differential slip rate circuit receive inputs from the calculator and differentiator and operate individually or in concert to detect a slip condition. An output circuit is connected to the excessive slip rate, prediction control, and excessive differential slip rate circuits to output a driving wheel slip control signal when at least one of the above circuits detects a slip condition.

Traction control system for controlling slip of a driving wheel of a

A vehicular anti-lock control method including the steps of comparing a wheel speed with a reference value which is based on a vehicle speed estimated from the wheel speed, judging the locking tendency of a wheel from the result of such comparison and reducing a brake pressure to be applied to the wheel which is on the way to locking, a first vehicle speed is estimated based on the speed of a wheel including a driving wheel and a second vehicle speed is estimated based on the speed of a follower wheel, the driving wheel being judged to be in a racing state when the first vehicle speed is larger than the second vehicle speed above a predetermined value. When the driving wheel is racing, the first vehicle speed is held constant and as far as such racing is present the constant vehicle speed is used to determine the reference value for comparison with the wheel speed.

Anti-lock control method for vehicle

A signal value on the basis of a lower wheel speed is compared with a signal value on the basis of a high wheel speed and, when the difference therebetween is larger than a predetermined value, a higher vehicle speed of two previously estimated vehicle speeds is used for anti-lock control and a reference value with which a wheel speed will be compared is derived from such vehicle speed. Thus, a range of condition for judging that wheels of a vehicle are about to be locked is enlarged.

In estimating a vehicle speed from a wheel speed and comparing the wheel speed with a reference threshold provided on the basis of that vehicle speed to control the supplying of a hydraulic braking pressure to wheel brakes, when the wheel speed is larger than the estimated vehicle speed, a predetermined value is added to that estimated vehicle speed to amend the latter, and conversely, when the wheel speed is smaller than the estimated vehicle speed, a predetermined value is subtracted from that estimated vehicle speed to amend the latter. Thus, the amended values are used as an estimated vehicle speed for controlling the hydraulic braking pressure.

Method of estimating vehicle speed

A fail-safe control circuit which requires that all control units produce control signals to operate a controlled device. The control units receive a feedback signal used for comparing with the control signal. When the control signal and the feedback signal do not match, a power supply interruption or disagreement signal causes a relay to disconnect power to the controlled device placing the controlled device in a fail-safe state.

Growing community of inventors

Saitama, Japan

Tetsuji Muto