Acceleration control system for vehicles

Claim 2

In an emergency circuit for controlling tractive effort of traction vehicles, wherein emergency control means actuate first braking means in response to an indication of abnormal vehicle operation, a brake assurance circuit adapted to actuated additional braking means comprising: a. first relay means controlled by said emergency control means to hold off actuation of said additional braking means until the occurrence of said aforesaid indication; b. a source adapted to provide velocity signals having a magnitude proportional to instantaneous vehicle velocity; c. sampling means for periodically sampling said velocity signals to produce sampling signals; d. signal coupling means responsive to said sampling and velocity signals and producing an output indication during time intervals when the amplitude difference between said sampling and velocity signals has a magnitude corresponding to vehicle deceleration at a predetermined satisfactory rate; e. second relay means responsive to said output indication and connected to hold off actuation of said additional braking means during intervals when said vehicle decelerates at satisfactory rates.

Claim 3

The brake assurance circuit of claim 1, further comprising: a. a source of AC signals having a frequency substantially in excess of the rate at which said velocity signals are periodically sampled; b. means for providing said AC signals to said signal coupling means; c. said signal coupling means providing, as an output indication, AC output signals during time intervals when the amplitude difference between said sampling and velocity signals is intermediate a predetermined magnitude range representative of acceptable vehicle deceleration.

Claim 4

The brake assurance circuit of claim 2 wherein said sampling means comprises a source of periodically recurring sample pulses and wherein said velocity signals are sampled during the occurrence of said pulses to produce sampling signals having an amplitude which is a function of the instantaneous velocity signal during the occurrence of said pulses.

Claim 5

The brake assurance circuit of claim 3 wherein said emergency control means causes the removal of operating potential from said first relay means concurrent with an indication of abnormal operating condition and wherein said second relay means is connected to provide operating potential to said first relay means when the vehicle decelerates above a predetermined rate subsequent to the occurrence of said indication of abnormal vehicle operation.

Claim 6

The brake assurance circuit of claim 4 wherein said first relay means are constructed to hold off actuation of said additional braking means for a time subsequent to the removal of operating potential commensurate to the time normally required for the vehicle to attain a predetermined deceleration rate and wherein said second relay means provides to said first relay means pulses of operating potential for time intervals substantially commensurate to the occurrence of AC output signals, whereby said first relay means holds off actuation of said additional braking means during time periods when said vehicle decelerates at predetermined satisfactory rates.

Claim 7

The brake assurance circuit of claim 3 wherein the time duration between successive sampling pulses is substantially in excess of the time duration of each sample pulse and the sampling signals have a substantially constant amplitude for at least the majority of the time duration between successive pulses.

Claim 8

The brake assurance circuit of clAim 6 wherein said signal coupling means comprises: a. adding means for algebraically adding said DC velocity signal, said sampling signal and said alternating current signals to produce a composite signal comprising an alternating component and a DC component having a level varying as a function of the difference between said sampling signals and said velocity signals; b. AC amplifying means; c. means for coupling said composite signal to said AC amplifying means, said AC amplifying means being constructed to provide AC output signals solely during time intervals when the amplitude difference between said velocity signals and said sampling signals is intermediate a predetermined amplitude range.

Claim 9

In a traction vehicle control circuit an arrangement adapted to control vehicle operation responsive to whether vehicle acceleration is above or below a predetermined magnitude, comprising: a. a source adapted to provide a DC velocity signal having a magnitude proportional to instantaneous vehicle velocity; b. means for sampling said DC velocity signal at a predetermined sampling rate to produce a sampling signal comprising successive discrete portions each having a DC amplitude level which is proportional to the instantaneous amplitude of said velocity signal at the associated time of sampling; c. a source of alternating current signals having a frequency substantially greater than said sampling rate; d. signal coupling means connected to receive all of the aforesaid signals and providing an AC output signal during time intervals when the magnitude difference between said velocity signal and said sample signal is intermediate a predetermined amplitude range; e. utilization means connected to said output means and having different output states during the presence and absence of said AC output signal so as to provide an indication of whether vehicle acceleration is above or below a predetermined magnitude.

Claim 10

In a traction vehicle control circuit an arrangement adapted to control vehicle operation responsive to whether vehicle acceleration is above or below a predetermined magnitude, comprising: a. a source adapted to provide a DC velocity signal having a magnitude proportional to instantaneous vehicle velocity; b. means for sampling said DC velocity signal at a predetermined sampling rate to produce a sampling signal comprising successive discrete portions each having a DC amplitude level which is proportional to the instantaneous amplitude of said velocity signal at the associated time of sampling; c. a source of alternating current signals having a frequency substantially greater than said sampling rate; d. signal coupling means connected to receive all of the aforesaid signals and providing an AC output signal during time intervals when the magnitude difference between said velocity signal and said sample signal is intermediate a predetermined amplitude range; e. utilization means connected to said output means and having different output states during the presence and absence of said AC output signal so as to provide an indication of whether vehicle acceleration is above or below a predetermined magnitude.

Claim 11

In a traction vehicle control circuit the arrangement of claim 8 wherein said sampling means comprises: a. a source of pulses recurring at predetermined time intervals which are several orders of magnitude in excess of the time duration of each pulse; b. means for sequentially sampling said DC velocity signals during the occurrence of successive ones of said pulses and producing said sample signal wherein said successive discrete portions each have a substantially constant amplitude for at least the majority of said sampling period.

Claim 12

In a traction vehicle control circuit the arrangement of claim 9 wherein said signal coupling means comprises: a. adding means for algebraically adding said DC velocity signal, said sampling signal, and said alternating current signal to produce a composite signal comprising an alternating current component and a DC component having a level varying as a function of the difference between said velocity signal and said sampling signal; b. AC amplifying means; c. means for coupling said composite signal to said AC amplifying means being constructed to provide an AC output signal solely during time intervals when the magnitude difference between said velocity signal and said sampling signal is intermediate a predetermined amplitude range.

Claim 13

In a traction vehicle control circuit an arrangement adapted to provide an output indication indicative of whether vehicle deceleration is above or below a predetermined magnitude comprising: a. a source adapted to provide a DC velocity signal having a magnitude proportional to instantaneous vehicle velocity; b. pulse means for generating a train of timing pulses separated by equal sample time periods, each of which periods being several orders of magnitude in excess of the time duration of each pulse; c. sampling means connected to said source and pulse means for sampling said velocity signal during the occurrence of each of said timing pulses, said sampling means having signal stoRage means providing a sampling signal having successive amplitude levels each of which is substantially constant throughout one of said sample time periods; d. an operational amplifier having first and second inputs and an output providing a signal which is a function of the difference of signals applied to said first and second inputs; e. means for connecting said velocity signal and said sampling signal to said first and second inputs to derive from said output an output signal whose DC level varies during each one of said sample time periods as a function of vehicle acceleration; f. means coupled to the output of said operational amplifier for producing output indications in response to output signals whose DC level is of a predetermined magnitude.

Claim 14

In a traction vehicle control circuit an arrangement adapted to provide an output indication indicative of whether vehicle deceleration is above or below a predetermined magnitude comprising: a. a source adapted to provide a DC velocity signal having a magnitude proportional to instantaneous vehicle velocity; b. pulse means for generating a train of timing pulses separated by equal sample time periods, each of which periods being several orders of magnitude in excess of the time duration of each pulse; c. sampling means connected to said source and pulse means for sampling said velocity signal during the occurrence of each of said timing pulses, said sampling means having signal stoRage means providing a sampling signal having successive amplitude levels each of which is substantially constant throughout one of said sample time periods; d. an operational amplifier having first and second inputs and an output providing a signal which is a function of the difference of signals applied to said first and second inputs; e. means for connecting said velocity signal and said sampling signal to said first and second inputs to derive from said output an output signal whose DC level varies during each one of said sample time periods as a function of vehicle acceleration; f. means coupled to the output of said operational amplifier for producing output indications in response to output signals whose DC level is of a predetermined magnitude.