Dewy,

Great information.

I do know the ABS system uses valves, and a reservoir to close off the brake line and accommodate in coming pedal pressure.

Dewy give us more information about this pump you speak of, what it's called and where I could get one?

The last thing you mentioned was, "ABS is just traction control when the brakes are on." Would that mean if one could activate the system with out the brakes applied, would it work like a traction control system?

I got this... (I'm a diesel mechanic, ABS specialist.)

Some older (junked) school buses had early version abs that required a pump that could be pulled off separately for service (which never needed it). One of these pumps would give you AMPLE braking power. They're made to run on 12v systems, even weatherproof. All you would need is two hydraulic T-way solenoids to re-route each rear wheel cylinder to either the vehicle factory system or the pump, as per arduino command. The arduino can get is traction control signals directly from the wheel sensors.

Here's how:
First, the anatomy of and ABS wheel sensor. - Most common wheel sensors are actually just a magnet with a coil wrapped around it. This sensor when placed close enough to a rotating sensor ring will distort the magnetic field of the sensor. This causes a signal to be generated but only when the wheel turns.

Second, the Arduino. - Having inputs tapped from the wheel sensor, the arduino looks for one input to go silent. (Stuck wheel, other wheel spinning wildly.) The Arduino then fires up the pump, activates the solenoid for the spinning wheel and clamps the brake until the other wheel rotates at a similar speed. (Usually within 10% tolerance.)

Tada. Basic traction control the way industry does it!
Advanced traction control is just more signal evaluation between the all four wheels plus throttle reduction, ABS is just traction control applied when the brake lights are on.

Hope it helps.

Hello elsp1991,

Using a window motor as a servo is a great solution to this system. In the mean time, I had the idea of piggy backing the ABS system it self. Instead of a linear actuator, or motor controlling the brake, why not use the ABS pump it self. Potentially the ABS pump has valves, that close off the break pedal to individual brake lines, and then applies brake line pressure using the ABS pump (you need a 4 channel/valved pump).

Great attention to detail with the VR sensor. I never thought about that, however, I do agree that tapping into the VR signal could create extra draw that would alter the signal into the ABS system. At the moment, the only thing I could think to do, would be to mount an additional sensors. The traction control system I intend to use was only for off road use, and would not be using, and/or disabling the ABS during use. Here is a notion, the brake pedal signal could disable the traction control system during use, thus working independently from the traction control (set relays/logic gates to toggle signal feed into TCS). With that notion, I do not believe the ABS actually works until you hit the pedal, because it does not randomly brake while driving (excluding any vehicle with on board TCS traction control system).

Back to linear or window motors mounted to a floating axle. The unsprung weight of the floating axle causes a lot of G-force on what ever is mounted to it. I would be cautious to sensitive, or precious electronics being mounted to this type of environment (don't forget about water).

Also, I'm pretty stoked that at least one other person is interested in this topic.

The vehicle is a Toyota 4Runner, and it does have a differential.

I was thinking of a similar idea where the arm of the servo would swing across these switches to monitor location. You give me a lot of great idea, and is exactly what I was looking for. I like the idea of monitoring torque with excessive spikes in amps. This idea reminds me of window motors, when they reach there limits while moving a glass window up and down in a door frame.

I had another idea where the center position is located with a magnetic switch, and the left and right positions would be timed pulses to get the servo arm to its location away from center.

For example, the window motor would be powered in one direction for 1 second, and then return to center, waiting for the next left or right 1 second pulse.

Thanks for your help cr0sh.

Is it possible to rig a window motor with 3 magnetic switches to locate center, 90 degrees left, and 90 degrees right, similar to a servo?

I have seen a lot of tutorials to build a window motor servo.
http://www.fieroaddiction.com/servo.html
But, I do not need precise movement, and I want to use magnetic switches because I believe they are waterproof.

I am unclear about how much torque a window motor can produce. Although, I do know these motors are used for robotics competitions because they are cheap, strong, and easily turned into servos. I saw a build on a simulator chair where these motors were capable of moving an average sized man plus the weight of the chair on demand.

http://www.x-simulator.de/forum/my-simple-sim-motion-chair-t1667.html

The cost effectiveness was definitely a challenge to prove that this could be done without a lot of funding, but more ingenuity. A rear locker for a vehicle could cost $500 to $800. On the lower end of the spectrum, a linear actuator could cost $100. Two actuators, plus the electronics, may start to get closer to the cost of a locker.

My original idea was to piggy back a 4 channel anti lock brake system, unfortunately the vehicle has a 3 channel ABS. This would not allow the individual braking of the rear wheels

Snooping around the web, I stumbled upon the window motor servo. They are roughly $15 - $20 and don't take too much effort to get running. Thanks for your information. I was unaware there was an off the self solution to this project.

The traction control system operates at speeds of 0.5 to maybe 5 mph. I do not think I would be skimping out by using these motors, with the exception to the extra step needed to waterproof them. I would have to factor that in, how much cost and effort it would take to waterproof a motor of that kind. As far as precision is concerned, I will not need precise movements.

I do have experience on the locker used on the Toyota Tacoma. It uses a window like motor, and is exposed to watery environments. Actually, they were poorly designed for water, and many malfunctioned shortly after use. I had to refurbish and reseal the one I owned and it did not take too much effort.

I am an ECG Tech, and when I see that on the screen, that means you are getting electrical noise. During The ECG process, the right leg wire is a ground. I see noise when this wire is not connected. Also, when instruments in the room are not properly grounded, the noise will be picked up by the machine.

I plan to build an off road traction control system roughly based on this link.
http://blog.chryslerllc.com/blog.do;jsessionid=F83B4BCDB38454BD1A43D066882C5EAE?id=270&p=entry

My truck has wheel sensors on each rear wheel to monitor speed. I will have an arduino monitor the wheel speed of each wheel, and when the percentage of change reaches a certain tolerance, the arduino will intervene the faster spinning wheel by applying brake force to the e-brake cable.

I have seen a lot of tutorials to build a window motor servo.
http://www.fieroaddiction.com/servo.html

The servo will apply the needed force to operate the brake cable.

The servo I need for the project needs to be waterproof. My thoughts were, if I used the pot to monitor degrees of motion, then the water proofing portion of this task would be much more difficult.

And, I only need the servo to be in a center position, 90 degrees left, or 90 degrees right. I had an idea of using magnetic switches, similar to home alarm systems. The switches are sealed, and assumably waterproof.

If I had a switch for each position of the servo arm(3, left, right, and center), would I be able to make this work with an arduino?

I plan to build an off road traction control system roughly based on this link.
http://blog.chryslerllc.com/blog.do;jsessionid=F83B4BCDB38454BD1A43D066882C5EAE?id=270&p=entry

My truck has wheel sensors on each rear wheel to monitor speed. I will have an arduino monitor the wheel speed of each wheel, and when the percentage of change reaches a certain tolerance, the arduino will intervene the faster spinning wheel by applying brake force to the e-brake cable.

I have seen a lot of tutorials to build a window motor servo.
http://www.fieroaddiction.com/servo.html

The servo will apply the needed force to operate the brake cable.

The servo I need for the project needs to be waterproof. My thoughts were, if I used the pot to monitor degrees of motion, then the water proofing portion of this task would be much more difficult.

And, I only need the servo to be in a center position, 90 degrees left, or 90 degrees right. I had an idea of using magnetic switches, similar to home alarm systems. The switches are sealed, and assumably waterproof.

If I had a switch for each position of the servo arm(3, left, right, and center), would I be able to make this work with an arduino?

Hello,
I have a project I'm working on and need a starter idea to get things going.
I was planing to build essentially a window motor servo, except I do
not need the infinite degrees of movement.
I plan on having this servo arm turn left, right or back to center. It
needs to be water proof, so my thoughts was, if I could get away from
having a pot sense degrees of movement, then I could easily make the
motor water proof. I did see motors like this where two positions were
involved. There was a switch to sense one position and a switch to
sense the other. I thought this made it simple to locate the position
of the motor turning.

FYI, I did some browsing and could not find related topics; I fear being the lazy guy who did not search.