US 9,960,716 B2Granted

Control timing and sequencing for a multi-phase electric motor

AssigneeAllegro MicroSystems, LLC

InventorsLyndon Ambruson, Robert Stoddard

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Abstract

Described embodiments provide an electronic circuit for controlling a motor. The electronic circuit includes a magnetic field sensing circuit responsive to magnetic field sensing elements disposed to sense rotation of the motor. The magnetic field sensing elements generate magnetic field signals, each having a state indicative of at least one of the rotational position and a rotation speed of the motor. A position and speed sensing circuit generates a signal representative of the rotational position of the motor and tracks state changes of the magnetic field signals. A gate driver circuit generates motor drive signals that drive the motor based upon the sensed rotational position. The position and speed sensing circuit generates a qualified control signal based upon a determined valid state change of the magnetic field signals. The gate driver circuit generates the motor drive signals based, at least in part, upon the qualified control signal.

Claims33

Dependent claims

An electronic circuit for controlling a motor, comprising:

a magnetic field sensing circuit responsive to a plurality of magnetic field sensing elements disposed to sense rotation of the motor and configured to generate a respective plurality of magnetic field signals, each having a respective state indicative of a rotational position of the motor;
a position and speed sensing circuit configured to generate a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor, wherein the position and speed sensing circuit tracks state changes of the plurality of magnetic field signals;
and
a gate driver circuit configured to generate one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position, wherein the one or more motor drive signals control a voltage applied to the motor;
wherein the position and speed sensing circuit is configured to generate at least one qualified control signal based upon a determined valid state change of the plurality of magnetic field signals, and
wherein the gate driver circuit is configured to generate the one or more motor drive signals based, at least in part, upon the qualified control signal,
wherein the position and speed sensing circuit is configured to modify one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor
wherein the position and speed sensing circuit is configured to:
determine that an invalid state change of the plurality of magnetic field signals has occurred when the motor direction indicator is not set and the current state indicator is not equal to an expected value determined based upon the previous state indicator, wherein no qualified control signal is generated for each invalid state change.

10 more elements

An electronic circuit for controlling a motor, comprising:

a magnetic field sensing circuit responsive to a plurality of magnetic field sensing elements disposed to sense rotation of the motor and configured to generate a respective plurality of magnetic field signals, each having a respective state indicative of a rotational position of the motor;
a position and speed sensing circuit configured to generate a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor, wherein the position and speed sensing circuit tracks state changes of the plurality of magnetic field signals;
and
a gate driver circuit configured to generate one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position, wherein the one or more motor drive signals control a voltage applied to the motor;
wherein the position and speed sensing circuit is configured to generate at least one qualified control signal based upon a determined valid state change of the plurality of magnetic field signals, and
wherein the gate driver circuit is configured to generate the one or more motor drive signals based, at least in part, upon the qualified control signal,
wherein the position and speed sensing circuit is configured to modify one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor
wherein the position and speed sensing circuit is configured to:
determine that a valid state change of the plurality of magnetic field signals has occurred when the motor direction indicator is not set and the current state indicator is equal to an expected value determined based upon the previous state indicator;
and
generate, for each valid state change, the at least one qualified control signal.

12 more elements

An electronic circuit for controlling a motor, comprising:

a magnetic field sensing circuit responsive to a plurality of magnetic field sensing elements disposed to sense rotation of the motor and configured to generate a respective plurality of magnetic field signals, each having a respective state indicative of a rotational position of the motor;
a position and speed sensing circuit configured to generate a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor, wherein the rotational position is associated with state changes of the plurality of magnetic field signals;
and
a gate driver circuit configured to generate one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position, wherein the one or more motor drive signals control a voltage applied to the motor;
wherein the position and speed sensing circuit is configured to generate at least one qualified control signal a predetermined number of times for an associated valid state change of the plurality of magnetic field signals;
wherein the position and speed sensing circuit is configured to modify one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor;
wherein the position and speed sensing circuit is configured to:
determine that a valid state change of the plurality of magnetic field signals has occurred when the motor direction indicator is not set and the current state indicator is equal to an expected value determined based upon the previous state indicator;
and
generate, for each valid state change the at least one qualified control signal.

11 more elements

An electronic circuit for controlling a motor, comprising:

a magnetic field sensing circuit responsive to a plurality of magnetic field sensing elements disposed to sense rotation of the motor and configured to generate a respective plurality of magnetic field signals, each having a respective state indicative of a rotational position of the motor;
a position and speed sensing circuit configured to generate a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor, wherein the rotational position is associated with state changes of the plurality of magnetic field signals;
and
a gate driver circuit configured to generate one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position, wherein the one or more motor drive signals control a voltage applied to the motor;
wherein the position and speed sensing circuit is configured to generate at least one qualified control signal a predetermined number of times for an associated valid state change of the plurality of magnetic field signals;
wherein the position and speed sensing circuit is configured to modify one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor;
wherein the position and speed sensing circuit is configured to:
determine that an invalid state change of the plurality of magnetic field signals has occurred when motor direction indicator is not set and the current state indicator is not equal to an expected value determined based upon the previous state indicator, wherein no qualified control signal is generated for each invalid state change.

9 more elements

A method of controlling a motor by a motor control circuit, the method comprising:

sensing, responsive to a plurality of magnetic field sensing elements, a rotational position of the motor;
generating a respective plurality of magnetic field signals, each having a respective state indicative of the sensed rotational position of the motor;
generating a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor;
tracking state changes of the plurality of magnetic field signals;
generating one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position of the motor, wherein the one or more motor drive signals control a voltage applied to the motor;
and
generating at least one qualified control signal a predetermined number of times for an associated valid state change of the plurality of magnetic field signals,
modifying one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor;
determining that a valid state change of the plurality of magnetic field signals has occurred when the motor direction indicator is not set and the current state indicator is equal to an expected value determined based upon the previous state indicator;
and
generating, for each valid state change, the at least one qualified control signal.

12 more elements

A method of controlling a motor by a motor control circuit, the method comprising:

sensing, responsive to a plurality of magnetic field sensing elements, a rotational position of the motor;
generating a respective plurality of magnetic field signals, each having a respective state indicative of the sensed rotational position of the motor;
generating a signal representative of at least one of the rotational position of the motor and a rotational speed of the motor;
tracking state changes of the plurality of magnetic field signals;
generating one or more motor drive signals that drive the motor based, at least in part, upon the sensed rotational position of the motor, wherein the one or more motor drive signals control a voltage applied to the motor;
and
generating at least one qualified control signal a predetermined number of times for an associated valid state change of the plurality of magnetic field signals;
modifying one or more status indicators based upon the state of the plurality of magnetic field signals, wherein the one or more status indicators comprise:
a previous state indicator associated with at least one previous state of the plurality of magnetic field signals;
a current state indicator associated with a current state of the plurality of magnetic field signals;
and
a motor direction indicator, wherein the motor direction indicator is set to one of a plurality of values based upon a detected direction of rotation of the motor and a desired direction of rotation of the motor;
determining that an invalid state change of the plurality of magnetic field signals has occurred when motor direction indicator is not set and the current state indicator is not equal to an expected value determined based upon the previous state indicator;
and
ignoring an invalid state change of the plurality of magnetic field signals until the motor direction indicator is set for a predetermined number of consecutive state changes of the plurality of magnetic field signals;
and
when the motor direction indicator has been set for the predetermined number of consecutive state changes:
generating the at least one qualified control signal;
and
clearing the motor direction indicator to a value associated with a valid state change.

17 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/056,287Filed 29 Feb 2016
Published: US 2017/0250634 A131 Aug 2017
Granted: 1 May 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H02P 6/17
Circuit arrangements for detecting position: and for generating speed information
H02P 6/16
Electronic commutators: circuit arrangements for detecting position
H02P 6/182
Without separate position detecting elements: using back-emf in windings
H02P
Control or regulation of electric motors, electric generators or dynamo-electric converters