Abstract: A device for measuring action force of a wheel includes a vehicle axle upon which the wheel is mounted, the vehicle axle having a stress neutral line, and a stress detecting sensor having at least one strain gauge. The stress detecting sensor is disposed within the vehicle axle so as to detect at least one of a horizontal shear stress and a vertical sheer stress with the at least one strain gauge being one of aligned with or proximate the stress neutral line thereby permitting substantial removal of axle torque influence from an output of the stress detecting sensor. A signal processing circuit processes the output of the stress detecting sensor.

Abstract: A method for cyclically controlling the braking of a vehicle includes the following steps: (a) detecting a road surface frictional force of said vehicle, (b) detecting a brake fluid pressure, and (c) controlling the brake fluid pressure in response to detected values including the brake fluid pressure and the road surface frictional force, the controlling including decreasing the brake fluid pressure in response to the road surface frictional force declining during an increase of the brake fluid pressure and increasing the brake fluid pressure in response to the road surface frictional force declining during fall-off of the brake fluid pressure.

Abstract: A device for measuring action force of a wheel includes a vehicle axle upon which the wheel is mounted, the vehicle axle having a stress neutral line, and a stress detecting sensor having at least one strain gauge. The stress detecting sensor is disposed within the vehicle axle so as to detect at least one of a horizontal shear stress and a vertical sheer stress with the at least one strain gauge being one of aligned with or proximate the stress neutral line thereby permitting substantial removal of axle torque influence from an output of the stress detecting sensor. A signal processing circuit processes the output of the stress detecting sensor.

Abstract: A stress composite sensor has a plurality of sensor elements each including a base plate and a stress sensor disposed thereon for delivering stress signals indicating stress in one direction alone. The sensor elements have the base plates fixed together in a common plane to form a sensor segment wherein the stress sensors are provided at intervals to provide signals indicating stress in the one direction. The stress sensors optionally each include strain gauges and in an embodiment include four strain gauges. The sensor elements are arranged in rows in an embodiment and are optionally integrally fixed together.

Abstract: A vehicular antilock brake control system does not require a lengthy extension piping from its actuator. The system provides for an accurate controlling method for maximizing a calculated road surface friction coefficient. Each wheel has a control unit consisting of a stress sensor, a controller and an actuator installed at the respective wheel. A stress value is detected, representative of road surface friction value or road surface friction coefficient value, for the corresponding wheel independently of the other wheels. In response to the output signal of the sensor, the controller regulates the actuator which controls brake fluid pressure applied to the respective wheel.

Abstract: A stress composite sensor has a plurality of sensor elements each including a base plate and a stress sensor disposed thereon for delivering stress signals indicating stress in one direction alone. The sensor elements have the base plates fixed together in a common plane to form a sensor segment wherein the stress sensors are provided at intervals to provide signals indicating stress in the one direction. The stress sensors optionally each include strain gauges and in an embodiment include four strain gauges. The sensor elements are arranged in rows in an embodiment and are optionally integrally fixed together.

Abstract: The road surface friction sensor of this invention comprises means for measuring the strain of the tire or around the wheel of a vehicle. By using this sensor, a vehicle antilock braking device can be constructed which is adapted to cyclically increase the pressure of brake fluid while the road surface frictional force increases in response to elevation of brake fluid pressure, decrease the brake fluid pressure when the road surface frictional force declines despite elevation of brake fluid pressure and increase the brake fluid pressure again when the road surface frictional force has declined in response to fall-off of brake fluid pressure. The output signal from the above road surface friction sensor can be subjected to mathematical operation to find a road surface friction coefficient.

Abstract: The invention provides a wheel-acting force measuring device free from the influences of cross talk due to brake torque (torsional torque).

Abstract: An ABS apparatus according to the present invention has an arbitrary number of first sensors (15, 16) capable of obtaining road frictional force information according to road frictional force F acting between a wheel of a car and a road on which the car is moving and braking torque information according to braking torque T acting between the wheel of the car and a braking equipment, a differential parameter calculating means (21) for calculating a differential parameter M according to the road frictional force information and the braking torque information from these first sensors (15, 16), and a solenoid valve controlling means (23) for starting and then stopping a pressure reducing operation when the differential parameter M calculated by the differential parameter calculating means (21) reaches a first threshold provided according to a peak value of the differential parameter M or a second threshold having an absolute value slightly smaller than that of the first threshold while the barking equipment is in

Abstract: A wheel-acting force measuring system for measuring for measuring force generated by a wheel having a road contacting surface is provided. The system includes an axle having a brake disk attachment portion and a spindle portion extending outwardly from the brake disk attachment portion to which the wheel is mounted, and a stress detecting sensor embedded in the spindle portion at a position between the brake disc attachment portion and a plane perpendicular to the road contacting surface of the wheel. In an embodiment there is further provided a brake caliper having a brake caliper angle defined by a caliper fixing axis and a wheel traveling direction, and the stress detecting sensor is mounted substantially at the brake caliper angle with respect to the wheel traveling direction and parallel to the caliper fixing axis.

Abstract: An antilock braking system employing stress sensors installed in the wheel axle structure of a motor vehicle. The stress sensors measure a road surface frictional force and a braking torque. A parameter M is calculated from these measured values. An ABS control terminates a braking pressure reduction process in accordance with the change in the parameter M. Thereby, the system can preclude the locking of the wheel of the motor vehicle even when the brake is suddenly applied, can prevent the braking pressure reduction from being over controlled, and makes possible to minimize the braking loss.

Abstract: A vehicular antilock brake control system does not require a lengthy extension piping from its actuator. The system provides for an accurate controlling method for maximizing a calculated road surface friction coefficient. Each wheel has a control unit consisting of a stress sensor, a controller and an actuator installed at the respective wheel. A stress value is detected, representative of road surface friction value or road surface friction coefficient value, for the corresponding wheel independently of the other wheels. In response to the output signal of the sensor, the controller regulates the actuator which controls brake fluid pressure applied to the respective wheel.

Abstract: In an anti-lock brake system mounted on a vehicle wherein when the vehicle is braked in an emergency during running, an increase in the road surface friction force or road surface friction coefficient owing to an increase in the brake pressure is detected by a road surface friction force detecting device or road surface friction coefficient detecting device. The optimum control start point associated with an increase in the signal value of the road surface friction force F or road surface friction coefficient &mgr; provided by the road surface friction force detecting device or road surface friction coefficient detecting device is decided by using a decrease in the wheel speed, i.e., by using the wheel speed &ohgr; or d&ohgr;/dt. Thereafter, from the point where the specified value of control based on F or &mgr;, or dF/dt or d&mgr;/dt, the brake pressure is moved from the pressure increasing mode to the pressure retaining or decreasing mode.

Abstract: A system is provided wherein road surface friction is sensed by measuring strain on a structure of a vehicle in a vicinity of a wheel of the vehicle. A road surface friction coefficient is determined by measuring strain on a structure of the vehicle in the vicinity of the wheel to produce signal outputs proportional to road surface frictional force and vertical load, and calculating the road surface friction coefficient from the outputs.

Abstract: In an anti-lock brake system mounted on a vehicle wherein when the vehicle is braked in an emergency during running, an increase in the road surface friction force or road surface friction coefficient owing to an increase in the brake pressure is detected by a road surface friction force detecting device or road surface friction coefficient detecting device. The optimum control start point associated with an increase in the signal value of the road surface friction force F or road surface friction coefficient &mgr; provided by the road surface friction force detecting device or road surface friction coefficient detecting device is decided by using a decrease in the wheel speed, i.e., by using the wheel speed &ohgr; or d&ohgr;/dt. Thereafter, from the point where the specified value of control based on F or &mgr;, or dF/dt or d&mgr;/dt, the brake pressure is moved from the pressure increasing mode to the pressure retaining or decreasing mode.

Abstract: An antilock braking system employing stress sensors installed in the wheel axle structure of a motor vehicle. The stress sensors measure a road surface frictional force and a braking torque. A parameter M is calculated from these measured values. An ABS control terminates a braking pressure reduction process in accordance with the change in the parameter M. Thereby, the system can preclude the locking of the wheel of the motor vehicle even when the brake is suddenly applied, can prevent the braking pressure reduction from being over controlled, and makes possible to minimize the braking loss.

Abstract: A device for measuring action force of a wheel includes a vehicle axle upon which the wheel is mounted, the vehicle axle having a stress neutral line, and a stress detecting sensor having at least one strain gauge. The stress detecting sensor is disposed within the vehicle axle so as to detect at least one of a horizontal shear stress and a vertical sheer stress with the at least one strain gauge being one of aligned with or proximate the stress neutral line thereby permitting substantial removal of axle torque influence from an output of the stress detecting sensor. A signal processing circuit processes the output of the stress detecting sensor.

Abstract: A stress composite sensor has sensor elements each including a base plate having a rectangular configuration and a first main surface and a second main surface opposite the first main surface, a pair of first strain gauges disposed on the first main surface crossing one another, a pair second strain gauges disposed on a the second main surface crossing one another, the first pair of strain gauges and the second pair of strain gauges being symmetrically disposed with respect to a center plane of the base plate; and bridge circuits incorporating the first pair of strain gauges and the second pair of strain gauges. The sensor elements include X-sensor elements for measuring stress in an X-direction, Y-sensor elements for measuring stress in a Y-direction, and Z-sensor elements for measuring stress in a Z-direction. Arithmetic circuits calculate stress from outputs of the bridge circuits.

Abstract: An antilock braking system employing stress sensors installed in the wheel axle structure of a motor vehicle. The stress sensors measure a road surface frictional force and a braking torque. A parameter M is calculated from these measured values. An ABS control terminates a braking pressure reduction process in accordance with the change in the parameter M. Thereby, the system can preclude the locking of the wheel of the motor vehicle even when the brake is suddenly applied, can prevent the braking pressure reduction from being over controlled, and makes possible braking loss mininization.

Abstract: Action force of a wheel is measured in order to measure the road surface frictional force, vertical drag, road surface friction coefficient, etc. Means for making these measurements can be constituents of an antilock brake system, traction control system, etc. These constituents may also serve as devices for measuring stresses generated in other structures. In a specific example, axle of a vehicle is formed with a hole, a stress detection sensor is installed in the hole and secured in position with the aid of a spacer element, and a detection signal from the stress detection sensor is processed in a signal processing circuit.