Trailer control system

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;
• an algorithm for calculating braking forces to correct forces selected from the group consisting of braking forces, yaw forces, and rollover forces stored in the memory;
• 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, and 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)}+c5ay|>Yroll,
• Then T roll = [ K ϕ ⁢ ⁢ K . ϕ ⁢ ⁢ K ay ] ⁢ [ ϕ ϕ . a y , ]
• where c3, c4 and c5 are coefficients, Φ is a roll angle, {dot over (Φ)} is a roll rate, ay is a lateral acceleration, Yroll is a predetermined or dynamically-determined threshold value, Troll is an amount of torque required in each wheel to correct a roll-over, and K is a gain.

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, wherein if yaw forces are present the method uses an algorithm for calculating a required braking force for each wheel on the prime mover and trailer to overcome the yaw forces, and the algorithm is
• If (c1|{dot over (ψ)}d−{dot over (ψ)}|+c2|ηd−η|)>Yyaw,
• Then T yaw = [ K ψ - K η ] ⁡ [ Ψ . d - Ψ . η d - η ] ,
• where c1 and c2 are coefficients, {dot over (ψ)}d is a desired yaw rate, {dot over (ψ)} is a yaw rate, ηd is a desired articulation angle, η is an articulation angle, Yyaw is a predetermined or dynamically-calculated threshold value, Tyaw is a torque applied to a wheel to overcome a yaw rate, and K is a gain.

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, wherein if rollover forces are present the method uses an algorithm for calculating braking forces and wherein the algorithm for calculating braking forces calculates a required torque force for each wheel on the trailer to overcome rollover forces, and the algorithm is
• If |c3Φ+c4{dot over (Φ)}+c5ay|>Yroll,
• Then T roll = [ K ϕ ⁢ ⁢ K . ϕ ⁢ ⁢ K ay ] ⁢ [ ϕ ϕ . a y , ]
• where c3, c4 and c5 are coefficients, Φ is a roll angle, {dot over (Φ)} is a roll rate, ay is a lateral acceleration, Yroll is a predetermined or dynamically-determined threshold value, Troll is an amount of torque required in each wheel to correct a roll-over, and K is a gain.