Setting the input shaping parameters¶
Copter has a set of parameters that define the way the aircraft feels to fly. This allows the aircraft to be set up with a very aggressive tune but still feel like a very docile and friendly aircraft to fly.
The most important of these parameters is:
PILOT_Y_RATE: desired maximum yaw rate in deg/s
ANGLE_MAX: maximum lean angle
ATC_ACCEL_P_MAX: Pitch rate acceleration
ATC_ACCEL_R_MAX: Roll rate acceleration
ATC_ACCEL_Y_MAX: Yaw rate acceleration
ATC_ANG_LIM_TC: Aircraft smoothing time
ATC_INPUT_TC: Time to achieve 63% seady state pitch and roll attitude. Mulitply by 3 to determine time to achieve steady state attitude.
PILOT_Y_RATE_TC: Time to achieve 63% steady state yaw rate. Multiply by 3 to determine time to achieve steady state rate.
Autotune will set the ATC_ACCEL_P_MAX, ATC_ACCEL_R_MAX and ATC_ACCEL_Y_MAX parameters to their maximum based on measurements done during the Autotune tests. These values should not be increased beyond what Autotune suggests without careful testing. In most cases pilots will want to reduce these values significantly.
For aircraft designed to carry large directly mounted payloads, the maximum values of ATC_ACCEL_P_MAX, ATC_ACCEL_R_MAX and ATC_ACCEL_Y_MAX should be reduced based on the minimum and maximum takeoff weight (TOW):
ATC_ACCEL_P_MAX x (min_TOW / max_TOW)
ATC_ACCEL_R_MAX x (min_TOW / max_TOW)
ATC_ACCEL_Y_MAX x (min_TOW / max_TOW)
ATC_ANG_LIM_TC may be increased to provide a very smooth feeling on the sticks at the expense of a slower reaction time.
Aerobatic aircraft should keep the ATC_ACCEL_P_MAX, ATC_ACCEL_R_MAX and ATC_ACCEL_Y_MAX provided by autotune and reduce ATC_ANG_LIM_TC to achieve the stick feel desired by the pilot. For pilots wanting to fly ACRO the following input shaping parameters can be used to tune the feel of ACRO:
The full list of input shaping parameters are: