accelerator position sensor

[merk]

Hi,
here you can see how accelerator position sensor works.

Two way variabile resistor switch, one providin 0,3 to 1,7 V other 0,6 to 3,4 V. I gues ECU check both readings to be more or less identical (by a factor 2 as in this case).

My question is if I could make a simple (no CAN) cruise control by generatin voltage output on those two signal pins?
This will actualy be power cruise not speed cruise control but wih a simple up down key you could increase/decrease speed.
and of course my board will have brake and clutch swith reading to disenage in the event one is depressed.

Could I send voltage siganl directly to 2 pins (via diode) or should the accelerator pedal be siconnected by a rellay when cruise is active?

I know this is not how a cruise is done, but I think will works just as well. And CAN BUS communication is to complex to implement.

Maybe I could get a tacho sensor reading as well to get the actual speed, and make a board that will try to adjust accelerator signal to maintain tacho signal constant.

One more think. If I use PWM with a small capacitor would this work?

 

[shortbus=]

Personally I think if you try this you will be a danger on the roads.

 

[picbits]

I've made a unit before to simulate this on test vehicles using a small PIC and a D2A converter - the PIC does the calcs for any vehicle including PWM throttle control and reverse voltage swings i.e. 1-4v track A and 2-0.5v track B etc and can be controlled via USB / Serial or analog in after setting up the base parameters. I can't share more than that I'm afraid as it was a corporate project but yes, easy enough to simulate / emulate.

 

[merk]

Personally I think if you try this you will be a danger on the roads.

it wouldnt be DOT tested yes, but it will have brake clutch disenage as well as on/off mechanical switch so i dont think i would be any danger on the road. danger on the road are people wrong doing not technology.
You can help me with the question but other than that please keep for your self.

 

[Diver300]

it wouldnt be DOT tested yes, but it will have brake clutch disenage as well as on/off mechanical switch so i dont think i would be any danger on the road. danger on the road are people wrong doing not technology.
You can help me with the question but other than that please keep for your self.

I was going to suggest brake and clutch override as a minimum.

I don't think that constant throttle will be adequate.

Here is a graph of the traction current (units of 25 mA, battery voltage around 400 V) for my car when driving on the cruise control, and then stopping. Averages, min and max are taken for each minute.

As you can see, the power demand was far from steady

For reference, here is the speed graph.

Now that is with adaptive speed control, and there were some hills, but if the power varies that much to keep a relatively constant speed, constant power will result in very variable speed. You need speed control / feedback.