Vehicle speed control circuit
First Claim
1. In a vehicle having a source of a pulsed vehicle road speed signal of a frequency proportional to the vehicle road speed and a throttle control means, a speed control circuit for automatically maintaining the speed of the vehicle at a desired road speed, comprising:
- means actuated by the vehicle operator when the vehicle reaches the desired road speed and responsive to the first vehicle road speed signal pulse to occur after said actuation for generating a first signal having a magnitude which is a function of the time elapsed from the occurrence of said first pulse;
means responsive to said first pulse generating a second signal having a magnitude which is a different function of the time elapsed from the occurence of said first pulse;
means for comparing the magnitudes of said first and second signals and for terminating the generation of said first signal when said magnitudes coincide wherein said means for generating said first signal stores said first signal as the desired road speed signal; and
comparator and control signal generating means responsive to the vehicle road speed signal and said desired road speed signal for generating a control signal to have the throttle control means to maintain the speed of the vehicle at the desired road speed.
3 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for automatically maintaining the speed of a vehicle at a desired road speed as selected by the vehicle operator. When the operator actuates the control circuit, a desired road speed signal proportional to the vehicle road speed at that moment is generated and stored. The stored desired road speed signal is continuously compared with a signal representing the vehicle road speed to generate a duty cycle modulated control signal to a throttle control which adjusts the vehicle throttle to maintain the desired road speed. The generation of the desired road speed signal is synchronized with the vehicle road speed signal to provide an accurate and highly repeatable desired road speed signal. The control circuit also includes an anticipatory control which responds to the operator actuation of the control circuit to pre-position the throttle control as the desired road speed signal is being generated and stored. This reduces the overall response time of the speed control circuit.
62 Citations
11 Claims
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1. In a vehicle having a source of a pulsed vehicle road speed signal of a frequency proportional to the vehicle road speed and a throttle control means, a speed control circuit for automatically maintaining the speed of the vehicle at a desired road speed, comprising:
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means actuated by the vehicle operator when the vehicle reaches the desired road speed and responsive to the first vehicle road speed signal pulse to occur after said actuation for generating a first signal having a magnitude which is a function of the time elapsed from the occurrence of said first pulse; means responsive to said first pulse generating a second signal having a magnitude which is a different function of the time elapsed from the occurence of said first pulse; means for comparing the magnitudes of said first and second signals and for terminating the generation of said first signal when said magnitudes coincide wherein said means for generating said first signal stores said first signal as the desired road speed signal; and comparator and control signal generating means responsive to the vehicle road speed signal and said desired road speed signal for generating a control signal to have the throttle control means to maintain the speed of the vehicle at the desired road speed. - View Dependent Claims (2, 3)
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4. In a vehicle having a source of a pulsed vehicle road speed signal of a frequency proportional to the vehicle road speed and a throttle control means, a speed control circuit for automatically maintaining the speed of the vehicle at a desired road speed, comprising:
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a set point means actuated by the vehicle operator when the vehicle reaches the desired road speed and responsive to the first vehicle road speed signal pulse to occur after said actuation for generating a set signal; means responsive to said set signal for generating a first signal having a magnitude which is a function of the time elapsed from the occurrence of said first pulse; means responsive to said first pulse for generating a second signal having a magnitude which is a different function of the time elapsed from the occurrence of said first pulse; means for comparing the magnitudes of said first and second signals and for generating a reset signal when the magnitudes coincide wherein said means for generating said first signal is responsive to said reset signal to terminate the generation of said first signal and includes means to store said first signal as the desired road speed signal; and comparator and control signal generating means responsive to the vehicle road speed signal and said desired road speed signal for generating a duty cycle modulated control signal to the throttle control means to maintain the speed of the vehicle at the desired road speed. - View Dependent Claims (5, 6, 7, 8, 9)
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10. In a vehicle having a source of a vehicle road speed signal and a throttle control means, a speed control circuit for automatically maintaining the speed of the vehicle at a desired road speed, comprising:
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means actuated by the vehicle operator when the vehicle reaches the desired road speed for generating a desired road speed signal; comparator and control signal generating means responsive to the vehicle road speed signal and said desired road speed signal for generating a duty cycle modulated control signal to the throttle control means to maintain the speed of the vehicle at the desired road speed; and anticipatory control means responsive to said actuation of said means for generating a desired road speed signal for removing the vehicle road speed signal from an input of said comparator and control signal means to drive said control signal to a 100 percent duty cycle to pre-position the throttle of the vehicle. - View Dependent Claims (11)
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Specification