Trailer control system

• US 20020095251A1
• Filed: 11/16/2001
• Published: 07/18/2002
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Funke, Scott, Oh, Pahngroc, Pavlov, Kevin J.
• Granted Patent: US 6,668,225 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 7/20 specially for trailers, e.g. in case of uncoupling of or overrunning by trailer inertia-actuated overrun brakes B60T13/08
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04
• CPC Class Codes: B60T 8/243 for roll-over protection
• CPC Class Codes: B60T 8/246 Change of direction
• CPC Class Codes: B60T 8/248 Trailer sway, e.g. for preventing jackknifing

Abstract

A trailer control system incorporates sensors on both the trailer and a tow vehicle towing the trailer to measure operating parameters of both the trailer and the tow vehicle or prime mover. A computer mounted in the trailer or in the tow vehicle gathers input data from the sensors, including a variety of measurements of force, displacement, and temperature for the tow vehicle, the trailer, and their components. The computer may also be used to apply braking forces to the wheels of the trailer. Using the simulator, a variety of components on the trailer may be tested, their performance measured, and a better trailer may be designed. A trailer may also incorporate such a system for better control of the trailer and the combination vehicle of which it is a part.

Claims

1. A control system for a combination vehicle having a prime mover and a trailer, the control system comprising:

a computer;

a memory accessible to said computer;

sensors operably connected to said computer;

output signals from said computer; and

at least two brake controllers for wheels on the trailer, said brake controllers in communication with said computer, wherein the computer receives inputs from sensors on the combination vehicle and calculates brake movements to control movement of the combination vehicle.

2. The control system of claim 1, further comprising an algorithm for calculating braking forces to correct forces selected from the group consisting of braking forces, yaw forces, and rollover forces.

3. The control system of claim 2, further comprising an algorithm for calculating braking forces required to equalize a speed of a left wheel and a speed of a right wheel to minimize an articulation angle between the prime mover and the trailer.

4. The control system of claim 2, wherein the algorithm for calculating braking forces calculates a required braking force for each wheel on the prime mover and trailer to overcome yaw forces, and said algorithm is

If (c₁|{dot over (ψ

)}_d−

{dot over (ψ

)}|+c₂|η

_d−

η

|)>

γ

_yaw,

Then

$T_{\mathrm{yaw}}=\left[K_{\mathrm{\psi <br><br>}}-K_{\mathrm{\eta <br><br>}}\right]<br><br>\left[\begin{array}{c}{\stackrel{.}{\mathrm{\Psi <br><br>}}}_d-\stackrel{.}{\mathrm{\Psi <br><br>}}\\ {\mathrm{\eta <br><br>}}_d-\mathrm{\eta <br><br>}\end{array}\right],$

where c₁ and c₂ are coefficients, {dot over (ψ

)}_d is a desired yaw rate, {dot over (ψ

)} is a yaw rate, η

_d is a desired articulation angle, η

is an articulation angle, γ

_yaw is a predetermined or dynamically-calculated threshold value, T_yaw is a torque applied to a wheel to overcome a yaw rate, and K is a gain.

5. The control system of claim 2, wherein the algorithm for calculating braking forces calculates a required torque force for each wheel on the trailer to overcome rollover forces, and said algorithm is

If |c₃φ

+c₄{dot over (φ

)}+c₅a_y|γ

_roll,

Then

$T_{\mathrm{roll}}=\left[K_{\mathrm{\varphi <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\stackrel{.}{K}}_{\mathrm{\varphi <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>K_{\mathrm{ay}}\right]<br><br>\text{\hspace{1em}<br><br>}\left[\begin{array}{c}\mathrm{\varphi <br><br>}\\ \stackrel{.}{\mathrm{\varphi <br><br>}}\\ a_{y,}\end{array}\right]$

where c₃, c₄ and c₅ are coefficients, φ

is a roll angle, {dot over (φ

)} is a roll rate, a_y is a lateral acceleration, γ

_roll is a predetermined or dynamically-determined threshold value, T_roll is an amount of torque required in each wheel to correct a roll-over, and K is a gain.

6. The control system of claim 1, wherein the sensors are selected from the group consisting of a temperature sensor, a yaw rate sensor, an accelerometer, a force sensor, a string potentiometer, a speedometer, a wheel speed sensor, a torque sensor, and a steering-wheel angle sensor.

7. The control system of claim 1, further comprising at least one brake on each wheel of the prime mover and the trailer, said brake selected from the group consisting of a hydraulic brake, an electric drum brake, and a variable reluctance brake.

8. The control system of claim 1, further comprising an electronic control module between the computer and the sensors, wherein the electronic control module receives signals from the sensors and conditions said signals for input to the computer.

9. The control system of claim 8, further comprising a digital signal processor connected between the electronic control module and the computer, wherein the digital signal processor receives outputs from the electronic control module, processes the outputs, and sends the outputs to the computer.

10. A method of controlling braking of a combination vehicle, the method comprising:

measuring a plurality of parameters relating to movements and speed of a prime mover and a trailer;

calculating at least one steering error selected from the group consisting of a braking error, a yaw steering error, and a trailer roll;

calculating a correction to a speed of at least one wheel on the trailer to correct the steering error; and

applying said correction by applying a braking force to the at least one wheel.

11. The method of claim 10, wherein the parameters are selected from the group consisting of a prime mover speed, a prime mover steering wheel angle, a trailer speed, a yaw rate, an acceleration, an articulation angle, a wheel speed, a wheel temperature, a wheel torque, a brake temperature, a brake pedal force, and a trailer hitch force.

12. The method of claim 10, wherein the steering error is a braking error, and further comprising measuring an articulation angle, comparing the articulation angle to a desired threshold articulation angle, and applying a correction to the trailer wheels to equalize a speed of a left and a right trailer wheel.

13. The method of claim 10, wherein the steering error is a vehicle yaw error, and further comprising calculating whether the yaw steering error is an oversteer or an understeer, calculating a direction of the error, and applying a correction to at least one wheel of the prime mover and one wheel of the trailer.

14. The method of claim 10, wherein the steering error is a trailer roll, and further comprising calculating whether the trailer roll is greater than a threshold value, calculating a direction of the roll, and applying a braking force to a wheel of the trailer to correct the roll if the trailer roll is greater than the threshold value.

16. The method of claim 15, wherein the operating parameters are selected from the group consisting of a prime mover speed, a prime mover steering wheel angle, a trailer speed, a yaw rate, an acceleration, an articulation angle, a wheel speed, a wheel temperature, a wheel torque, a brake temperature, a brake pedal force, and a trailer hitch force.

17. The method of claim 15, further comprising:

measuring a response of the operating parameters to the braking force; and

adjusting the braking force to avoid understeering, oversteering, jackknifing, or rolling the trailer.

15. A method of operating a combination vehicle, the combination vehicle having a prime mover with separately-controlled brakes and a trailer having at least two wheels with separately-controlled brakes, the method comprising:

driving the combination vehicle;

detecting operating parameters of the combination vehicle; and

applying a braking force with separately controlled brakes in response to the operating parameters, to control a force on the trailer selected from the group consisting of a braking force, a yaw torque force, and a rollover force.