Method of controlling power delivered to an actuator assembly
AssigneeCambridge Mechatronics Limited
InventorsMark Easton, Christopher Avery, Nils Darphin
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Abstract
A method of controlling power delivered to an actuator assembly (2) comprising at least four actuator components (30) arranged, on actuation, to move a movable part (20) relative to a support structure (10), the method comprising: • scheduling PWM control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots; • and sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot.
Claims11
A method of controlling power delivered to an actuator assembly comprising at least four actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- and
- determining if the width of any PWM pulse is scheduled to be greater than the width of a respective sub-slot and sorting the PWM pulses by width into pairs upon positive determination thereof.
A method of controlling power delivered to an actuator assembly comprising at least four actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- and
- determining if the width of a PWM pulse previously sorted into a lower-width pair exceeds the width of another PWM pulse previously sorted into a higher-width pair by more than a threshold and sorting the PWM pulses by width into pairs upon positive determination thereof.
A method of controlling power delivered to an actuator assembly comprising at least four actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- and
- sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- wherein the width of each sub-slot is varied upon the sorting the PWM pulses by width into pairs.
A method of controlling power delivered to an actuator assembly comprising at least four actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- and
- sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- wherein the width of each sub-slot is equal to the sum of i) the width of the widest PWM pulse in the sub-slot and ii) a portion of a spare slot width available in the time slot after summing the widths of the widest PWM pulses of the pairs.
A method of controlling power delivered to an actuator assembly comprising at least eight actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least eight actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- and
- sorting the PWM pulses by width into at least four pairs, such that each pair of PWM pulses is applied in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- wherein a shortest sub-slot in which the shortest PWM pulse is applied and a longest sub-slot in which the longest PWM pulse is applied are scheduled adjacent to one another at the beginning or at the end of the time slot.
A method of controlling power delivered to an actuator assembly comprising at least four actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least four actuator components, wherein the PWM pulses are scheduled in a series of time slots defined by a PWM frequency, each time slot being divided into a plurality of sub-slots;
- sorting the PWM pulses by width into pairs, wherein each pair of PWM pulses is scheduled in a respective sub-slot and is allowed to overlap in the respective sub-slot;
- and
- determining the width of overlap of PWM pulses in each pair of PWM pulses, and increasing the duty and/or amplitude of overlapping PWM pulses in dependence on the width of overlap so as to compensate for electrical resistance in a common connection to the actuator components driven by the overlapping pulses, to thereby reduce the power reduction at the actuator components due to the electrical resistance in the common connection compared to a situation in which there is no compensation for electrical resistance in the common connection.
A method for controlling power delivered to an actuator assembly comprising at least two actuator components arranged, on actuation, to move a movable part relative to a support structure, the method comprising:
- scheduling pulse width modulated (PWM) control signals comprising a series of PWM pulses for driving actuation of the at least two actuator components, wherein at least some of the PWM pulses overlap;
- determining the width of overlap of overlapping PWM pulses;
- and
- increasing the duty and/or amplitude of overlapping PWM pulses in dependence on the width of overlap so as to compensate for electrical resistance in a common connection to the actuator components driven by the overlapping pulses, to thereby reduce the power loss due to the electrical resistance in the common connection compared to a situation in which there is no common connection to the actuator components.
Dependencies are inferred from the claim text.