Boots – shoes – and leggings
Patent
1988-06-02
1990-07-10
Lall, Parshotam S.
Boots, shoes, and leggings
180179, 123350, 123351, B60K 3104
Patent
active
049410989
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a constant speed drive unit in which a throttle valve of an automomobile is controlled by an actuator of the stepper motor type, and controllability is improved by variable gain control in which the throttle valve opening speed is variably controlled corresponding to the driving speed of the automobile. More particularly, the invention relates to a constant speed drive unit in which, when deviation between the set speed and the actual speed of the automobile is less than a specified level, variable gain control is invalidated and switched to constant gain control to improve controllability and stability.
BACKGROUND ART
Hitherto, in the constant speed drive unit or cruise control of the stepper motor type, the characteristic of the throttle valve opening speed with respect to the driving speed of the automobile (hereinafter referred to as "gain characteristic") is almost flat; in other words, a constant gain characteristic is given to the conventional constant speed unit.
Driving performance as well as acceleration performance varies depending on the type of automobile. For example, a sports car is better in driving performance than a commercial vehicle or a passenger car, and acceleration performance of a sports car is also higher. Accordingly, higher responsiveness is desired in the constant speed drive unit of the sports car, and the gain characteristic thereof is desired to be the approximately linear in a relation to drive speed thereof.
On the other hand, in commercial vehicle, high responsiveness is not required as it is with a sports car in view of the high loading capacity, but a flat gain characteristic is desired for every driving speed thereof.
In a passenger car, a linear characteristic similar to that of a sports car is required up to an intermediate speed region, while a saturation or lowering characteristic is desired in the high speed region in view of safety concerns.
Since a characteristic, whose gain characteristic is almost flat, is given to the conventional constant speed drive unit as mentioned above, a problem exists in that it is impossible to obtain a desirable gain characteristic flexibly corresponding to the type of automobile.
The present invention was made to solve the above problem and has an object of providing a constant speed drive unit in which the pulse motor speed is flexibly controlled corresponding to the gain characteristic, whereby controllability and stability are both improved.
SUMMARY OF THE INVENTION
In the constant speed drive unit according to the present invention, a speed signal is inputted to a broken line approximation circuit to obtain an analog output signal corresponding to a gain characteristic; the analog signal is inputted to a voltage/frequency converter to convert it to a reference pulse signal; the reference pulse signal and a pulse signal obtained from an encoder mounted on the actuator motor shaft are inputted to a phase comparator to obtain an output pulse signal having a pulse width proportional to a phase difference between the two signals; and PWM is carried out with either a triangular wave or a sawtooth wave after passing an integration circuit in the next step, so that drive control of the actuator motor is carried out by this modulated pulse. In this manner, the speed of the motor is controlled according to the gain characteristic and, as a result, a constant speed drive unit having a required gain characteristic is obtained.
Furthermore, by driving the pulse motor synchronously with the reference pulse, not only the speed of the pulse motor is controlled corresponding to the gain characteristic, but also the pulse motor is driven at a constant frequency when speed deviation between the set driving speed and the actual driving speed is less than a specified level, thereby improving the stability of the control.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of the constant speed drive unit according to the present invention;
FIG. 2 is a block diagram
REFERENCES:
patent: 3580355 (1971-05-01), Kitano et al.
patent: 3952829 (1976-04-01), Gray
patent: 4098242 (1978-07-01), Anderson
patent: 4120373 (1978-10-01), Fleischer
patent: 4248321 (1981-02-01), Collonia
patent: 4495454 (1985-01-01), Collonia
patent: 4553209 (1985-11-01), Hyodo et al.
patent: 4726187 (1988-02-01), Reinhardt et al.
Onishi Masayoshi
Yasukawa Takeshi
Lall Parshotam S.
Mitsubishi Denki & Kabushiki Kaisha
Trans V.
LandOfFree
Speed control unit for an automobile does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Speed control unit for an automobile, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Speed control unit for an automobile will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1724534