Trailer brake system and method
OwnerCharles G. Bess, Ken D. Burgininventors
Life of this patent
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Abstract
An electric-over-hydraulic braking system for trailers and towed vehicles is disclosed. The system comprises off-the-shelf components, such as a standard linear actuator and master cylinder, for reduced cost and greater reliability. In a dual master cylinder configuration, the braking system controller calculates an average pressure across each channel, and compares that value to a control signal from an in-cab controller. The linear actuator is extended or retracted in response to a signal proportional to this difference. The system may include break-away functionality, as well as diagnostics to indicate low pressure and transducer circuit malfunction conditions.
Claims19
A braking system for a vehicle and trailer system, comprising:
- (a) a master cylinder operable to hydraulically drive one or more sets of trailer brakes, said master cylinder comprising a bore;
- (b) a linear actuator comprising an extendible arm, said arm axially aligned with said master cylinder bore;
- (c) a plurality of transducers in hydraulic communication with said master cylinder;
- and
- (d) a controller in communication with said linear actuator and said transducers, and operable to manipulate said linear actuator, said controller comprising a transducer conditioning circuit operable to output an average transducer pressure value and comprising an adder in communication with said transducers to receive input from said transducers, and a divider in communication with said adder to receive input from said adder, and wherein said adder comprises an operational amplifier and said divider comprises at least one resistor.
A brake system for a trailer, comprising:
- (a) a vehicle brake controller;
- (b) a master cylinder comprising a plurality of channels;
- (c) a linear actuator in communication with said master cylinder;
- (d) a hydraulic line connected to each of said master cylinder channels;
- (e) a brake connected to each of said hydraulic lines;
- (f) a transducer in communication with each of said hydraulic lines, said transducers operable to generate a signal corresponding to the hydraulic pressure in said hydraulic lines;
- and
- (g) a trailer brake controller in communication with said linear actuator, said transducers, and said vehicle brake controller, wherein said trailer brake controller comprises a transducer conditioning circuit which comprises an adder in communication with said transducers to receive input from said transducers, and a divider in communication with said adder to receive input from said adder, and wherein said adder comprises an operational amplifier and said divider comprises at least one resister.
A method of controlling a braking system comprising a vehicle brake controller operable to generate a brake signal, an actuator operable to receive a control signal, and a plurality of transducers each operable to generate a pressure signal, comprising the steps of:
- (a) receiving the brake signal from the vehicle brake controller and the plurality of pressure signals from the transducers;
- (b) converting the brake signal from a pulse width modulated signal to a pure analog signal;
- (c) computing the approximate average of the pressure signals;
- (d) computing the difference between the brake signal and the average pressure signal to create the control signal wherein the control signal comprises an extend signal and a retract signal;
- (e) receiving the control signal at the actuator;
- and
- (f) manipulating the actuator in response to the control signal wherein said manipulating step comprises one of the extension of the actuator, the retraction of the actuator, and the holding in place of the actuator;
- (g) receiving from a break-away switch a break-away signal;
- and
- (h) extending the actuator in response to the break-away signal.
Dependencies are inferred from the claim text.