APM_control: Modified gain definitions for roll and pitch controllers so PID gains behave like previous servo PIDS
Gain definitions in roll and pitch controllers were updated previously
so that the old PID tuning values could be transferred across.
Updated tuning guide for revised gain definition.
master
Paul Riseborough12 years agocommitted byAndrew Tridgell
// @Description: This is the gain from pitch angle error to demanded pitch rate. It controls the time constant from demanded to achieved pitch angle. For example if a time constant from demanded to achieved pitch of 0.5 sec was required, this gain would be set to 1/0.5 = 2.0. A value of 1.0 is a good default and will work with nearly all models. Advanced users may want to increase this to obtain a faster response.
// @Description: This controls the time constant in seconds from demanded to achieved pitch angle. A value of 0.7 is a good default and will work with nearly all models. Advanced users may want to reduce this time to obtain a faster response but there is no point setting a time less than the aircraft can achieve.
// @Description: This is the gain from demanded pitch rate to demanded elevator. Provided CTL_PTCH_OMEGA is set to 1.0, then this gain works the same way as the P term in the old PID (PTCH2SRV_P) and can be set to the same value.
// @Description: This is the gain from pitch angle to elevator. This gain works the same way as PTCH2SRV_P in the old PID controller and can be set to the same value.
// @Description: This is the gain from pitch rate error to demanded elevator. This adjusts the damping of the pitch control loop. It has the same effect as the D term in the old PID (PTCH2SRV_D) but without the large spikes in servo demands. This will be set to 0 as a default. Some airframes such as flying wings that have poor pitch damping can benefit from a small value of up to 0.1 on this gain term. This should be increased in 0.01 increments as to high a value can lead to a high frequency pitch oscillation that could overstress the airframe.
// @Description: This is the gain from pitch rate to elevator. This adjusts the damping of the pitch control loop. It has the same effect as PTCH2SRV_D in the old PID controller and can be set to the same value, but without the spikes in servo demands. This gain helps to reduce pitching in turbulence. Some airframes such as flying wings that have poor pitch damping can benefit from increasing this gain term. This should be increased in 0.01 increments as too high a value can lead to a high frequency pitch oscillation that could overstress the airframe.
// @Description: This is the gain for integration of the pitch rate error. It has essentially the same effect as the I term in the old PID (PTCH2SRV_I). This can be set to 0 as a default, however users can increment this to make the pitch angle tracking more accurate.
// @Description: This is the gain applied to the integral of pitch angle. It has the same effect as PTCH2SRV_I in the old PID controller and can be set to the same value. Increasing this gain causes the controller to trim out constant offsets between demanded and measured pitch angle.
// @Description: This is the gain from pitch angle error to demanded pitch rate. It controls the time constant from demanded to achieved pitch angle. For example if a time constant from demanded to achieved pitch of 0.5 sec was required, this gain would be set to 1/0.5 = 2.0. A value of 1.0 is a good default and will work with nearly all models. Advanced users may want to increase this to obtain a faster response.
// @Description: This controls the time constant in seconds from demanded to achieved bank angle. A value of 0.7 is a good default and will work with nearly all models. Advanced users may want to reduce this time to obtain a faster response but there is no point setting a time less than the aircraft can achieve.
// @Description: This is the gain from demanded roll rate to demanded aileron. Provided CTL_RLL_OMEGA is set to 1.0, then this gain works the same way as the P term in the old PID (RLL2SRV_P) and can be set to the same value.
// @Description: This is the gain from bank angle to aileron. This gain works the same way as the P term in the old PID (PTCH2SRV_P) and can be set to the same value.
// @Description: This is the gain from pitch rate error to demanded elevator. This adjusts the damping of the roll control loop. It has the same effect as the D term in the old PID (RLL2SRV_D) but without the large spikes in servo demands. This will be set to 0 as a default. This should be increased in 0.01 increments as too high a value can lead to high frequency roll oscillation.
// @Description: This is the gain from roll rate to aileron. This adjusts the damping of the roll control loop. It has the same effect as PTCH2SRV_D in the old PID controller but without the spikes in servo demands. This gain helps to reduce rolling in turbulence. It should be increased in 0.01 increments as too high a value can lead to a high frequency pitch oscillation that could overstress the airframe.
// @Description: This is the gain for integration of the roll rate error. It has essentially the same effect as the I term in the old PID (RLL2SRV_I). This can be set to 0 as a default, however users can increment this to enable the controller trim out any roll trim offset.
// @Description: This is the gain from the integral of bank angle to aileron. It has the same effect as PTCH2SRV_I in the old PID controller. Increasing this gain causes the controller to trim out steady offsets due to an out of trim aircraft.
// @Description: This sets the maximum roll rate that the controller will demand (degrees/sec). Setting it to zero disables the limit. If this value is set too low, then the roll can't keep up with the navigation demands and the plane will start weaving. If it is set too high (or disabled by setting to zero) then ailerons will get large inputs at the start of turns. A limit of 60 degrees/sec is a good default.
// @Description: This sets the maximum roll rate that the controller will demand (degrees/sec). Setting it to zero disables the limit. If this value is set too low, then the roll can't keep up with the navigation demands and the plane will start weaving. If it is set too high (or disabled by setting to zero) then ailerons will get large inputs at the start of turns. A limit of 60 degrees/sec is a good default.
Paul Riseborough
12 years ago
committed by
Andrew Tridgell