Mirror
/
ardupilot
mirror of https://github.com/ArduPilot/ardupilot
5
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

AP_MotorsMulticopter: Add current limit time constant variable

This commit is contained in:
Leonard Hall 2016-06-08 20:54:32 +09:00 committed by Randy Mackay
parent 7e0e0ca874
commit be25ac4acf
2 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
libraries/AP_Motors/AP_MotorsMulticopter.cpp
View File

@ -116,6 +116,14 @@ const AP_Param::GroupInfo AP_MotorsMulticopter::var_info[] = {
// @User: Advanced
AP_GROUPINFO("SPIN_ARM", 19, AP_MotorsMulticopter, _spin_arm, AP_MOTORS_SPIN_ARM_DEFAULT),
// @Param: BAT_CURR_TC
// @DisplayName: Motor Current Max Time Constant
// @Description: Time constant used to limit the maximum current
// @Range: 0 10
// @Units: Seconds
// @User: Advanced
AP_GROUPINFO("BAT_CURR_TC", 20, AP_MotorsMulticopter, _batt_current_time_constant, AP_MOTORS_BAT_CURR_TC_DEFAULT),
// @Param: THST_HOVER
// @DisplayName: Thrust Hover Value
// @Description: Motor thrust needed to hover expressed as a number from 0 to 1
@ -207,7 +215,6 @@ void AP_MotorsMulticopter::update_throttle_filter()
}
// return current_limit as a number from 0 ~ 1 in the range throttle_min to throttle_max
//todo: replace this with a variable P term
float AP_MotorsMulticopter::get_current_limit_max_throttle()
{
// return maximum if current limiting is disabled
@ -224,7 +231,8 @@ float AP_MotorsMulticopter::get_current_limit_max_throttle()
float batt_current_ratio = _batt_current/_batt_current_max;
_throttle_limit += AP_MOTORS_CURRENT_LIMIT_P*(1.0f - batt_current_ratio)/_loop_rate;
float loop_interval = 1.0f/_loop_rate;
_throttle_limit += (loop_interval/(loop_interval+_batt_current_time_constant))*(1.0f - batt_current_ratio);
// throttle limit drops to 20% between hover and full throttle
_throttle_limit = constrain_float(_throttle_limit, 0.2f, 1.0f);

3
libraries/AP_Motors/AP_MotorsMulticopter.h
View File

@ -23,7 +23,7 @@
#define AP_MOTORS_BAT_VOLT_MAX_DEFAULT 0.0f // voltage limiting max default
#define AP_MOTORS_BAT_VOLT_MIN_DEFAULT 0.0f // voltage limiting min default (voltage dropping below this level will have no effect)
#define AP_MOTORS_BAT_CURR_MAX_DEFAULT 0.0f // current limiting max default
#define AP_MOTORS_CURRENT_LIMIT_P 0.2f // replace with parameter - Sets the current limit P term
#define AP_MOTORS_BAT_CURR_TC_DEFAULT 5.0f // Time constant used to limit the maximum current
#define AP_MOTORS_BATT_VOLT_FILT_HZ 0.5f // battery voltage filtered at 0.5hz
// spool definition
@ -153,6 +153,7 @@ protected:
AP_Float _batt_voltage_max; // maximum voltage used to scale lift
AP_Float _batt_voltage_min; // minimum voltage used to scale lift
AP_Float _batt_current_max; // current over which maximum throttle is limited
AP_Float _batt_current_time_constant; // Time constant used to limit the maximum current
AP_Int16 _pwm_min; // minimum PWM value that will ever be output to the motors (if 0, vehicle's throttle input channel's min pwm used)
AP_Int16 _pwm_max; // maximum PWM value that will ever be output to the motors (if 0, vehicle's throttle input channel's max pwm used)
AP_Float _throttle_hover; // estimated throttle required to hover throttle in the range 0 ~ 1