Using an Arduino to control trailer brake actuator

I want to use an Arduino to send a control signal to a Titan Brakerite electric over hydraulic brake actuator. I have a trailer brake controller that outputs a 0 to 12 Volt signal to the actuator now, and that works fine.

I want to replace that controller with an Arduino. Since the Arduino cannot send a signal that goes from 0 to 12 Volts and draws up to an Amp of current, I need something else to drive the signal. I have tried a potentiometer, and transistor circuit of my own design. Neither worked, since the input impedance of the actuator is quite low.

I was thinking of using an L298N motor driver in the circuit, but will not have a chance to try that out for a few days. Do you think that will work? Any other ideas?

Thank you.

Daanii: I want to replace that controller with an Arduino.

Don't do it unless you FIRST get written approval from your liability insurer.

...R

+1 on the 'do not do it'. The commercial trailer brake controller is a piece of equipment that has undergone massive amount of research, design and testing to prevent failure.

I want to do this as part of a test vehicle I am building that will never be driven on the roads. So we will make sure the safety issue is covered.

I have bought and disassembled a couple of trailer brake controllers, and while they are not complicated devices, reverse engineering them is a little difficult. I thought someone else might have done this and could help me out.

PS: I also wondered if a L298N motor driver would work in an application like this. I know that motor drivers are designed for motors and other inductive loads and may not give linear output like I want to get. Again, I thought perhaps someone might know about that.

Daanii: I want to do this as part of a test vehicle I am building that will never be driven on the roads. So we will make sure the safety issue is covered.

I have bought and disassembled a couple of trailer brake controllers, and while they are not complicated devices, reverse engineering them is a little difficult. I thought someone else might have done this and could help me out.

Without exposing any intellectual property secrets, what do you want to do that is different from the in-cab controller is doing?

Are you not able to connect the Arduino to the controller, as if it was the brake light wire, so as to simulate brake pedal pressing?

Paul

Good questions.

I am using the trailer brake actuator to be the brakes for my vehicle. The brakes are controlled by a paddle on a steering wheel controller. The driver of the vehicle pulls on the paddle to produce a braking signal, which the Arduino translates to a 0 to 5 Volt proportional output.

To operate the actuator, I need to translate that 0 to 5 Volt signal of a few milliamps to a 0 to 12 Volt signal of about 1/2 Amp, which is easy enough to do. Unfortunately, none of the methods I have tried to translate the signal have worked with the actuator. I think the input impedance of the actuator is too low for a voltage divider or the transistor circuit I tried.

They trailer brake controllers do not accept an electronic braking signal. They simply tap into the brake light signal, which is either on or off rather than proportional to the amount of braking force.

So trailer brake controllers do a lot of things that I do not need them to do, like converting the amount of time the brake pedal is depressed into a proportional braking signal, while not doing what I need them to do, which is accept a proportional braking signal and pass that along to the brake actuator.

That helps immensely! Someone is going to quickly tell you an Arduino DOES NOT have a 0-5 volt output.

But can produce a variable pulse width train of pulses. That might be used to control the brake pressure.

My pickup truck/5th wheel trailer has an electric brake controller that PWM the trailer brakes. I wonder if you might use the electronic controller for anti-lock braking and the associated solenoid to do your project.

Are you intending to control 4 wheels, or 2?

Paul

Paul, for now I am just doing the two back wheels using the same brake actuator. Later I want to put the front two wheels on a different brake actuator. And eventually I want to do all four brakes separately.

It turns out I was able to test out the L298N board just now using the brake actuator, and it works well. I still have to work out some of the details, and figure out a safety mechanism, but at least I got the thing to finally work electronically.

It is rather fun to control the brakes using a joystick paddle. The joystick goes into a laptop, which processes the data and sends a command to the Arduino, which sends a command to the L298N board, which sends a command to the brake actuator. That all needs to be simplified and made absolutely secure, but now that the thing works, I can start on that process.

Congratulations! One of the rare success stories.

Paul