Replace
motor.zero_electric_angle = zero_angle_toremember+ motor.shaft_velocity*gain;
by
motor.zero_electric_angle = zero_angle_toremember+ delta_el_angle;
Replace
motor.zero_electric_angle = zero_angle_toremember+ motor.shaft_velocity*gain;
by
motor.zero_electric_angle = zero_angle_toremember+ delta_el_angle;