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Technical support / PID control of two contradictory PWM signals
« on: February 19, 2024, 01:08:18 AM »
Hi all
Been a few years since last used trilogi stuff but have a few up coming projects that I plan to use FMD1616-10s. The issue I'm stuck on is
how to control the speed of an engine powering a large vacuum pump, the input signal uses two PWM signals acting together
1. Idle - full throttle 81 - 27 % PWM @ 5v 200 Hz
2. Idle - full throttle 17 - 73 % PWM @ 5v 200 Hz
The vacuum pump is direct driven at engine speed, 1400 rpm and in this case, the speed signal at this speed is 23 Hz, and scoping the throttle signals while operating the throttle manually indicates signal 1 at about 53% and signal 2 at about 46%. Ssooo.... what I need to do is work out some method of PID control over two control signals that move in opposite directions.
I would be quite willing to have a crack at sorting out a single channel control but the two opposing signal thing is a bit beyond me so any help would be greatly appreciated
Cheers Pete
Oh by the way, I assure you I'm not a student asking some one to do an assignment I should be doing myself
i
Been a few years since last used trilogi stuff but have a few up coming projects that I plan to use FMD1616-10s. The issue I'm stuck on is
how to control the speed of an engine powering a large vacuum pump, the input signal uses two PWM signals acting together
1. Idle - full throttle 81 - 27 % PWM @ 5v 200 Hz
2. Idle - full throttle 17 - 73 % PWM @ 5v 200 Hz
The vacuum pump is direct driven at engine speed, 1400 rpm and in this case, the speed signal at this speed is 23 Hz, and scoping the throttle signals while operating the throttle manually indicates signal 1 at about 53% and signal 2 at about 46%. Ssooo.... what I need to do is work out some method of PID control over two control signals that move in opposite directions.
I would be quite willing to have a crack at sorting out a single channel control but the two opposing signal thing is a bit beyond me so any help would be greatly appreciated
Cheers Pete
Oh by the way, I assure you I'm not a student asking some one to do an assignment I should be doing myself
i