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Copter: Leonard's alt-hold feed forward

This commit is contained in:
Randy Mackay 2013-04-01 16:10:44 +09:00
parent f82ce449d7
commit ee7f40cfe9
1 changed files with 9 additions and 1 deletions
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10
ArduCopter/Attitude.pde
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@ -1028,6 +1028,7 @@ get_throttle_rate(int16_t z_target_speed)
{
static uint32_t last_call_ms = 0;
static float z_rate_error = 0; // The velocity error in cm.
static float z_target_speed_last = 0; // The requested speed from the previous iteration
int32_t p,i,d; // used to capture pid values for logging
int16_t output; // the target acceleration if the accel based throttle is enabled, otherwise the output to be sent to the motors
uint32_t now = millis();
@ -1036,12 +1037,19 @@ get_throttle_rate(int16_t z_target_speed)
if( now - last_call_ms > 100 ) {
// Reset Filter
z_rate_error = 0;
output = 0;
} else {
// calculate rate error and filter with cut off frequency of 2 Hz
z_rate_error = z_rate_error + 0.20085f * ((z_target_speed - climb_rate) - z_rate_error);
// feed forward acceleration based on change in desired speed.
output = constrain(z_target_speed - z_target_speed_last, -300, 300); // ensure we do not have integer overflow
output *= 50; // To-Do: replace 50 with dt
}
last_call_ms = now;
// store target speed for next iteration
z_target_speed_last = z_target_speed;
// separately calculate p, i, d values for logging
p = g.pid_throttle.get_p(z_rate_error);
@ -1054,7 +1062,7 @@ get_throttle_rate(int16_t z_target_speed)
d = g.pid_throttle.get_d(z_rate_error, .02);
// consolidate target acceleration
output = p+i+d;
output += p+i+d;
#if LOGGING_ENABLED == ENABLED
// log output if PID loggins is on and we are tuning the yaw