A method of on-demand energy delivery to an active suspension system comprising an actuator body, hydraulic pump, electric motor, plurality of sensors, energy storage facility, and controller is provided. The method comprises disposing an active suspension system in a vehicle between a wheel mount and a vehicle body, detecting a wheel event requiring control of the active suspension; and sourcing energy from the energy storage facility and delivering it to the electric motor in response to the wheel event.

Active vehicle suspension system

A vehicle suspension system including: (a) a suspension spring interconnecting a vehicle body and a wheel; (b) an actuator having an electric motor, such that the actuator is capable of generating, based on a force of the electric motor, an actuator force forcing the body and the wheel toward and away from each other, and causing the generated actuator force to act as a damping force against displacement of the body and the wheel; and (c) a control device for controlling the actuator force generated by the actuator, by controlling operation of the electric motor. The control device is capable of establishing a constant-force generating state in which the actuator force is constantly generated as a constant actuator force by the actuator with supply of an electric power thereto from a battery as an electric power source of the electric motor such that the generated constant actuator force acts in a rebound direction or a bound direction. The control device controls the constant-force generating state, based on a charge state of the battery.

Vehicle suspension system

A wheel vibration information signal detected by an acceleration sensor (11) mounted on a wheel (1) or an in-tire gas pressure fluctuation information signal detected by a pressure sensor (31) mounted in a tire is subjected to frequency analysis by frequency analysis means (14 (34)), so as to detect the vibration spectrum or the pressure fluctuation spectrum band value. The vibration level of the detected band is compared to a vibration level correspondence table (15T) showing the relationship between the road surface friction coefficient μ stored in the vibration level storage means (15) and the vibration level. Alternatively, the detected pressure level is compared to a pressure fluctuation level correspondence table (35T) showing the relationship between the road surface friction coefficient μ stored in the pressure fluctuation level storage means (35) and the pressure fluctuation level. Thus, it is possible to accurately estimate the value of road surface friction coefficient μ, thereby improving the vehicle safety.

Method and apparatus for estimating road surface state and tire running state, ABS and vehicle control using the same

By passing the vertical acceleration through a phase adjusting filter and a gain adjusting filter, the phase of the vertical acceleration is advanced by 49 degrees so that the phase difference with respect to the actual relative velocity becomes 180 degrees in the neighborhood of the vehicle body resonance point, thereby making the phase of the vertical acceleration, in effect, coincident with the phase of the relative velocity In the neighborhood of the vehicle body resonance point (1 Hz), the gain of the estimated relative velocity takes a small value In frequency regions other than the neighborhood of the vehicle body resonance point, the gain of the estimated relative velocity is increased Consequently, the controlled variable in the neighborhood of the vehicle body resonance point increases, and the controlled variable in higher frequency regions decreases Damping force is adjusted in correspondence to the controlled variable Thus, it is possible to improve ride quality in the neighborhood of the vehicle body resonance point (1 Hz)

Suspension control system

A variable shock absorber assembly of the adaptive or semi-active type or an active actuator wherein the actuator, sensors, electronic controller and valving are integral to and integrated into one assembly and comprise one compact integral unit. Feedback control provides a signal proportional to and indicative of the actuator position and velocity. The compact system is temperature compensated by incorporating temperature sensors into the integrated assembly. The integrated system also provides diagnostics integral to the assembly and an LED mounted on the assembly for providing a visual indication of system condition.

Variable shock absorber with integrated controller, actuator and sensors

A suspension control system for automotive vehicles automatically adjusts the damping strength of variable shock absorbers or other dampers in accordance with road surface conditions as recognized by frequency analysis of a vehicle height or vibration sensor signal. The sensor signal reflects vertical displacement of the vehicle body from the road surface and includes high-frequency components due solely to displacement of the wheels or unsprung mass relative to the road surface and low-frequency components due to displacement of the vehicle body or sprung mass. The sensor signal is filtered into these separate frequency bands, the amplitude of each of which is compared to a corresponding reference level. The results of comparison give an indication of the degree and scale of irregularities in the road surface; specifically, a high-amplitude low-frequency component indicates larger-scale bumps and dips capable of bouncing the vehicle whereas a strong high-frequency component reflects a rough-textured road surface, such as gravel. The comparison information is sent to a suspension system controller which causes actuation of the shock absorbers to a stiffer mode of operation when the low-frequency sensor signal components are relatively strong.

Automotive suspension control system with road-condition-dependent damping characteristics

In a vehicle vibration damping force control system, rolling, pitching and bouncing motions are detected independently in a predetermined priority order; each detected motion is compared with respective predetermined levels; if each detected motion exceeds each predetermined level, hydraulic switch valves are controlled so that operating fluid energized by stroke changes of the hydraulic cylinders due to the detected vibration motion is passed through damping force generating mechanisms to increase a damping force against only the detected vibration motion, without generating any other damping forces against other non-detected vibration motions. Since only the necessary damping force is generated against only the detected vibration motion, the damping force is minimized to maintain vehicle riding comfort.

Vehicle vibration damping force control system

An automatic sound level control system for audio equipment comprises means for controlling the gain of an amplifier for amplifying an audio input signal in accordance with manually selected level and the ambient noise level so that the output sound level is increased with the ambient noise level. The rate at which the sound level is increased with ambient noise is controlled high when the preset sound level selected by the listener is low, while that rate is controlled low when the preset sound level is high.

Automatic sound level control system for audio equipment

PURPOSE:To produce a proper damping effect for a behavior by effecting control such that, when it is decided that behavior exceeds a set state, only working fluid energized by a stroke change responding to the behavior of each hydraulic cylinder is caused to pass a damping force generating mechanism. CONSTITUTION:A piping through which the two cylinder chambers of double acting type hydraulic cylinders A individually installed between four wheels and a car body are connected to each other between cylinders is provided. A damping force generating mechanism B to generate a damping force along with the passage of working fluid is communicated with the piping, and a switching valve C to be switcheable of a flow passage is provided. Based on an output signal from a behavior detecting means D to detect a signal responding to behavior of a vehicle, it is decided by a behavior deciding means E whether the behavior exceeds a set state. When it is decided that the behavior exceeds the set state the switch position of the switching valve C is controlled by a switching valve control means F so that only working fluid energized by a stroke change responding to the behavior of each hydraulic cylinder A is caused to pass through the damping force generating mechanism B.

Damping force control device for vehicle

PURPOSE: To improve the turning performance of a vehicle by applying the constitution wherein a roll rigidity sharing ratio is increased for either a front or rear suspension having compliance steering characteristics of high over- steering effect, when steering is judged to be in a state equal to or above the predetermined speed. CONSTITUTION: A vehicle is assigned with characteristics of different effect between front and rear wheel sides for increasing turning performances with compliance steering. In this case, a ratio of roll rigidity distribution between the front and rear sides of the vehicle is so made as to be variable via variation mechanisms A1 and A2. On the other hand, a judgement means B makes judgement as to whether the steering of the vehicle is equal to or above the predetermined condition. When the steering condition generates a speed equal to or above the predetermined level, a steering condition judgement means C controls roll rigidity distribution for increasing the roll rigidity sharing ratio of a suspension positioned at either front or rear part of the vehicle and having the compliance characteristics of high effectiveness to increase turning performance with the variation mechanisms A1 and A2. COPYRIGHT: (C)1991,JPO&Japio

Fukashi Sugasawa

Papers

Automotive suspension control system with road-condition-dependent damping characteristics

Vehicle vibration damping force control system

Automatic sound level control system for audio equipment

Damping force control device for vehicle

Front and rear distribution control device for vehicle roll rigidity