raisim::DcMotorParameters

struct · #include <raisim/object/ArticulatedSystem/MotorOperatingRegion.hpp>

Steady-state electrical model of the DC/BLDC motor inside an actuator, on the motor (rotor) side of the actuator's gear, in SI units. The operating region limits the motor's electromagnetic torque Kt i.

Public member functions

torquePerVolt

double torquePerVolt() const

Returns motor torque per volt, Kt / R [Nm/V]

backEmfDamping

double backEmfDamping() const

Returns slope of the voltage limit, Kt / (R Kv) [Nm s/rad]. A motor at its voltage limit acts as a damper with this coefficient.

stallTorque

double stallTorque() const

Returns torque at zero speed and full bus voltage, Kt Vbus / R [Nm]

noLoadSpeed

double noLoadSpeed() const

Returns speed at zero torque and full bus voltage, Kv Vbus [rad/s]

isValid

bool isValid() const

Returns true if R, Kt, Kv and Vbus are positive and finite, the peak torque is positive (it may be infinite), and the constants derived from them (torque per volt, stall torque, back-EMF damping, no-load speed) are positive and finite. Finite parameters can overflow the derived constants, which would make the region undefined. ArticulatedSystem::setActuators(), ArticulatedSystem::setBusVoltage() and the URDF loader reject invalid motors.

Public attributes

resistance

double resistance

winding resistance R [Ohm]

torqueConstant

double torqueConstant

torque constant Kt [Nm/A]

velocityConstant

double velocityConstant

velocity constant Kv [rad/s/V]. It is the inverse of the back-EMF constant.

busVoltage

double busVoltage

bus voltage Vbus [V]

peakTorque

double peakTorque

peak torque [Nm] at which the core saturates. Infinity leaves only the voltage limit.