Motor vehicles – Including one or more ski-like or runner members – With at least one surface-engaging propulsion element
Patent
1985-09-17
1987-05-05
Love, John J.
Motor vehicles
Including one or more ski-like or runner members
With at least one surface-engaging propulsion element
B62D 506
Patent
active
046624660
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a steering force controller for a power steering apparatus and particularly, to a steering force controller which electronically controls steering force in accordance with vehicle speed, steering rotational angle and so forth.
2. Discussion of Background
Recently, there has been developed a power steering apparatus utilizing a microcomputer. In this apparatus, a characteristic map of a predetermined control pattern is stored in a memory, and control inputs such as vehicle speed and steering rotational angle are input to the microcomputer. The microcomputer appropriately controls the steering force generated by a power cylinder, in accordance with these control inputs and the characteristic map.
For example, there is known an electronically controlled power steering apparatus of the type wherein the steering rotational angle is detected by providing an encoder secured to a steering shaft and by causing a counter to count up or down in response to the output of the encoder and in dependence upon the steering direction. In this apparatus, as the content of the counter for storing the steering rotational angle is lost due to an electric power loss, a steering rotational angle detected when the electric power is subsequently restored coincides with that as counted from the position where the steering is located at that time. Accordingly, it is necessary to detect a neutral position of the steering again and then, to modify the previously detected steering rotational angle to a steering rotational angle as counted from the neutral position. For example, in a detecting method utilizing the fact that most of the time the steering wheel is in a neutral position, the vehicle must run a considerable distance in order that the straight driving state or the neutral position of the steering can be precisely detected by sampling the output of the encoder each time of a unit driving distance or each unit driving time and by software processing the sampled data. Thus, the steering rotational angle so detected is unreliable at such a time that the vehicle has just begun to run after the supply of electric power. If the power assist were controlled based upon a signal indicative of a steering rotational angle which is detected in an early stage of driving, the operator would suffer a curious or unpleasant feeling.
SUMMARY OF THE INVENTION
The present invention is created to solve the foregoing problems, and the object of the present invention is to provide a steering force controller which when the vehicle has just been started, is capable of preventing a detection signal of steering rotational angle from having a large influence upon the control of power assist generated by an electronically controlled power steering apparatus.
A steering force controller according to the present invention includes steering force regulation means provided in a pressurized fluid circuit of power steering apparatus. The regulation means includes a solenoid and regulates the steering force generated by a power cylinder of the power steering apparatus, based upon the value of electric current applied to the solenoid. There is also provided a solenoid controller for applying to the solenoid a control electric current in response to signals from a vehicle speed detector and a steering angle detector and control means for reducing the control electric current to the solenoid. This control means reduces the control electric current to the solenoid until a time comes when a neutral position of the steering can be precisely detected after the supply of electric power.
In accordance with the present invention, at an early stage when the vehicle has just been started, the steering rotational angle has a small influence upon the steering force generated by the power cylinder. This can avoid that the driver suffers a curious or unpleasant feeling while the neutral position of the steering is not detected correctly at an early stage of driving.
Other objects, featur
REFERENCES:
patent: 4476529 (1984-10-01), Nakamura et al.
patent: 4552240 (1985-11-01), Takeshima et al.
Eto Kunihiko
Mori Yutaka
Ohno Akihiro
Love John J.
Toyoda Koki Kabushiki Kaisha
Watts Charles R.
LandOfFree
Steering force controller for a power steering apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Steering force controller for a power steering apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Steering force controller for a power steering apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2394296