From 65d36c44afdacc1ed4762fe63c3e0f8a4a6f1317 Mon Sep 17 00:00:00 2001 From: Julian Oes Date: Tue, 12 Mar 2013 12:12:23 -0700 Subject: Prevent flips at high throttle Conflicts: src/drivers/ardrone_interface/ardrone_motor_control.c --- .../ardrone_interface/ardrone_motor_control.c | 88 ++++++++++------------ 1 file changed, 38 insertions(+), 50 deletions(-) (limited to 'src/drivers/ardrone_interface/ardrone_motor_control.c') diff --git a/src/drivers/ardrone_interface/ardrone_motor_control.c b/src/drivers/ardrone_interface/ardrone_motor_control.c index ecd31a073..d3b414150 100644 --- a/src/drivers/ardrone_interface/ardrone_motor_control.c +++ b/src/drivers/ardrone_interface/ardrone_motor_control.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -369,11 +370,9 @@ void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls float yaw_control = actuators->control[2]; float motor_thrust = actuators->control[3]; - //printf("AMO: Roll: %4.4f, Pitch: %4.4f, Yaw: %4.4f, Thrust: %4.4f\n",roll_control, pitch_control, yaw_control, motor_thrust); - const float min_thrust = 0.02f; /**< 2% minimum thrust */ const float max_thrust = 1.0f; /**< 100% max thrust */ - const float scaling = 500.0f; /**< 100% thrust equals a value of 500 which works, 512 leads to cutoff */ + const float scaling = 510.0f; /**< 100% thrust equals a value of 510 which works, 512 leads to cutoff */ const float min_gas = min_thrust * scaling; /**< value range sent to motors, minimum */ const float max_gas = max_thrust * scaling; /**< value range sent to motors, maximum */ @@ -382,71 +381,56 @@ void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls float motor_calc[4] = {0}; float output_band = 0.0f; - float band_factor = 0.75f; const float startpoint_full_control = 0.25f; /**< start full control at 25% thrust */ - float yaw_factor = 1.0f; static bool initialized = false; /* publish effective outputs */ static struct actuator_controls_effective_s actuator_controls_effective; static orb_advert_t actuator_controls_effective_pub; - if (motor_thrust <= min_thrust) { - motor_thrust = min_thrust; - output_band = 0.0f; - } else if (motor_thrust < startpoint_full_control && motor_thrust > min_thrust) { - output_band = band_factor * (motor_thrust - min_thrust); - } else if (motor_thrust >= startpoint_full_control && motor_thrust < max_thrust - band_factor * startpoint_full_control) { - output_band = band_factor * startpoint_full_control; - } else if (motor_thrust >= max_thrust - band_factor * startpoint_full_control) { - output_band = band_factor * (max_thrust - motor_thrust); + /* linearly scale the control inputs from 0 to startpoint_full_control */ + if (motor_thrust < startpoint_full_control) { + output_band = motor_thrust/startpoint_full_control; // linear from 0 to 1 + } else { + output_band = 1.0f; } + roll_control *= output_band; + pitch_control *= output_band; + yaw_control *= output_band; + + //add the yaw, nick and roll components to the basic thrust //TODO:this should be done by the mixer // FRONT (MOTOR 1) motor_calc[0] = motor_thrust + (roll_control / 2 + pitch_control / 2 - yaw_control); - // RIGHT (MOTOR 2) motor_calc[1] = motor_thrust + (-roll_control / 2 + pitch_control / 2 + yaw_control); - // BACK (MOTOR 3) motor_calc[2] = motor_thrust + (-roll_control / 2 - pitch_control / 2 - yaw_control); - // LEFT (MOTOR 4) motor_calc[3] = motor_thrust + (roll_control / 2 - pitch_control / 2 + yaw_control); - // if we are not in the output band - if (!(motor_calc[0] < motor_thrust + output_band && motor_calc[0] > motor_thrust - output_band - && motor_calc[1] < motor_thrust + output_band && motor_calc[1] > motor_thrust - output_band - && motor_calc[2] < motor_thrust + output_band && motor_calc[2] > motor_thrust - output_band - && motor_calc[3] < motor_thrust + output_band && motor_calc[3] > motor_thrust - output_band)) { + /* if one motor is saturated, reduce throttle */ + float saturation = fmaxf(fmaxf(motor_calc[0], motor_calc[1]),fmaxf(motor_calc[2], motor_calc[3])) - max_thrust; + + + if (saturation > 0.0f) { + + /* reduce the motor thrust according to the saturation */ + motor_thrust = motor_thrust - saturation; - yaw_factor = 0.5f; - yaw_control *= yaw_factor; // FRONT (MOTOR 1) motor_calc[0] = motor_thrust + (roll_control / 2 + pitch_control / 2 - yaw_control); - // RIGHT (MOTOR 2) motor_calc[1] = motor_thrust + (-roll_control / 2 + pitch_control / 2 + yaw_control); - // BACK (MOTOR 3) motor_calc[2] = motor_thrust + (-roll_control / 2 - pitch_control / 2 - yaw_control); - // LEFT (MOTOR 4) motor_calc[3] = motor_thrust + (roll_control / 2 - pitch_control / 2 + yaw_control); } - for (int i = 0; i < 4; i++) { - //check for limits - if (motor_calc[i] < motor_thrust - output_band) { - motor_calc[i] = motor_thrust - output_band; - } - if (motor_calc[i] > motor_thrust + output_band) { - motor_calc[i] = motor_thrust + output_band; - } - } /* publish effective outputs */ actuator_controls_effective.control_effective[0] = roll_control; @@ -467,25 +451,29 @@ void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls /* set the motor values */ - /* scale up from 0..1 to 10..512) */ + /* scale up from 0..1 to 10..500) */ motor_pwm[0] = (uint16_t) (motor_calc[0] * ((float)max_gas - min_gas) + min_gas); motor_pwm[1] = (uint16_t) (motor_calc[1] * ((float)max_gas - min_gas) + min_gas); motor_pwm[2] = (uint16_t) (motor_calc[2] * ((float)max_gas - min_gas) + min_gas); motor_pwm[3] = (uint16_t) (motor_calc[3] * ((float)max_gas - min_gas) + min_gas); - /* Keep motors spinning while armed and prevent overflows */ - - /* Failsafe logic - should never be necessary */ - motor_pwm[0] = (motor_pwm[0] > 0) ? motor_pwm[0] : 10; - motor_pwm[1] = (motor_pwm[1] > 0) ? motor_pwm[1] : 10; - motor_pwm[2] = (motor_pwm[2] > 0) ? motor_pwm[2] : 10; - motor_pwm[3] = (motor_pwm[3] > 0) ? motor_pwm[3] : 10; - - /* Failsafe logic - should never be necessary */ - motor_pwm[0] = (motor_pwm[0] <= 511) ? motor_pwm[0] : 511; - motor_pwm[1] = (motor_pwm[1] <= 511) ? motor_pwm[1] : 511; - motor_pwm[2] = (motor_pwm[2] <= 511) ? motor_pwm[2] : 511; - motor_pwm[3] = (motor_pwm[3] <= 511) ? motor_pwm[3] : 511; + /* scale up from 0..1 to 10..500) */ + motor_pwm[0] = (uint16_t) (motor_calc[0] * (float)((max_gas - min_gas) + min_gas)); + motor_pwm[1] = (uint16_t) (motor_calc[1] * (float)((max_gas - min_gas) + min_gas)); + motor_pwm[2] = (uint16_t) (motor_calc[2] * (float)((max_gas - min_gas) + min_gas)); + motor_pwm[3] = (uint16_t) (motor_calc[3] * (float)((max_gas - min_gas) + min_gas)); + + /* Failsafe logic for min values - should never be necessary */ + motor_pwm[0] = (motor_pwm[0] > 0) ? motor_pwm[0] : min_gas; + motor_pwm[1] = (motor_pwm[1] > 0) ? motor_pwm[1] : min_gas; + motor_pwm[2] = (motor_pwm[2] > 0) ? motor_pwm[2] : min_gas; + motor_pwm[3] = (motor_pwm[3] > 0) ? motor_pwm[3] : min_gas; + + /* Failsafe logic for max values - should never be necessary */ + motor_pwm[0] = (motor_pwm[0] <= max_gas) ? motor_pwm[0] : max_gas; + motor_pwm[1] = (motor_pwm[1] <= max_gas) ? motor_pwm[1] : max_gas; + motor_pwm[2] = (motor_pwm[2] <= max_gas) ? motor_pwm[2] : max_gas; + motor_pwm[3] = (motor_pwm[3] <= max_gas) ? motor_pwm[3] : max_gas; /* send motors via UART */ ardrone_write_motor_commands(ardrone_write, motor_pwm[0], motor_pwm[1], motor_pwm[2], motor_pwm[3]); 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