Stopping Behavior

this page describes the configurable stopping behaviours of the motor controller when transitioning from an active driving state to a 0% throttle stopped state regardless of the configured stopping behavior, if an error condition that stops motor drive is encountered braking will not be applied (i e the freewheeling behavior will occur) the following behaviours can be configured stopping behaviour freewheeling when freewheeling is the configured stopping behavior, no braking will be applied when 0% throttle is commanded, drive will be disengaged and the motor will be allowed to freely spin some configurations do not allow the freewheeling stopping behaviour to be used please consult the following list if freewheeling on stop is important freewheeling cannot be used if any of the following configurations apply drive mode reversible drive topology focal propeller parking enabled passive hold when passive hold is the configured stopping behavior passive braking will be applied, this consumes no power when 0% throttle is commanded, the motor controller will begin to ramp the duty cycle down to 0% at the 'ramp to stop' rate until the output duty cycle reaches 0% then the passive braking will be applied by shorting the motor phases, creating a resistive force against turning active hold when active hold is the configured stopping behaviour an active braking force will be applied, this can be stronger than the passive braking force but it consumes power and generates heat when 0% throttle is commanded, the motor controller will begin to ramp the duty cycle down to 0% at the 'ramp to stop' rate until the output duty cycle reaches 0% then the active braking force will be applied which is an active duty cycle applied to the motor configured by the 'active hold strength' setting increasing the 'active hold strength' increases the braking force but also increases power consumption and heat generation stopping behavior on armed when the 'stopping behaviour on armed' setting is enabled, the above configured stopping behavior will be performed when the unit arms when disabled, the motor controller will be in a freewheeling state when armed gradual braking gradual braking can cause a regeneration effect and requires afw to be enabled gradual braking should not be enabled on uni directional power supplies gradual braking applies to both the passive hold and active hold stopping behaviors when enabled, before transitioning to either the passive or active holding states the gradual braking routine will take place the gradual braking routine gradually shorts the motor phases at an increasing duty cycle to provide a smoother braking action, once the output duty cycle has reached 0% configuring gradual braking the 'gradual braking starting duty cycle' setting determines what duty cycle of the phases being shorted the gradual braking routine will begin at the 'gradual braking duration' setting determines over what duration the phase shorting duty cycle will increase to 100%, meaning that the motor phases are shorted 100% of the time a longer duration for gradual braking will provide a smoother braking action and reduce the intensity of bus voltage increases higher inertia systems are recommended to use a longer duration of gradual braking over voltage behavior due to the regeneration effect of gradual braking, the bus voltage may increase during gradual braking this may lead to a bus over voltage event which can change the gradual braking behaviour based on the configured over voltage response over voltage response > hard shutdown motor drive will be disabled therefore leading to the freewheeling stopping behaviour gradual braking will be disabled and no braking force will be applied it is recommended to enable 'stopping behaviour on armed' so that a braking force will be applied once the over voltage event clears over voltage response > limit duty cycle output gradual braking will be disabled and the motor controller will proceed to the passive hold or active hold states immediately this will provide a more instantaneous braking force which may damage mechanical components in high intertia systems over voltage response > none gradual braking will be unaffected