Acceleration estimator for speed rate control
AssigneeDRS Power & Control Technologies, Inc.
InventorDavid J. Gritter
Life of this patent
Estimating the term…
Abstract
Embodiments of the present invention are directed to a controller that is configured to limit the rate of change of speed of a motor (e.g., the acceleration or deceleration) regardless of the operating mode of the motor (e.g., speed, torque, or power control mode). The controller can include an acceleration estimator which monitors the output speed of a motor and provides an acceleration-limited speed set point. The output of the acceleration estimator may be limited to a range of acceptable acceleration values that correspond to the required limits of acceleration and deceleration. The acceleration estimator can be configured such that it causes the speed regulator to override the torque and/or power regulators when the acceleration range is exceeded.
Claims20
A method comprising:
- measuring, by a speed sensor, an output speed of a motor;
- receiving, by an acceleration estimator, the output speed;
- determining, by the acceleration estimator, an acceleration estimate based on the output speed;
- determining, by the acceleration estimator, that the acceleration estimate is outside a preset range;
- calculating, by the acceleration estimator, a speed estimate based on a maximum acceleration value from the preset range;
- generating a speed set point based on the speed estimate;
- determining a speed error signal based on the speed set point and the output speed;
- outputting, by a speed regulator, a speed control signal based on the speed error signal;
- comparing the speed control signal from the speed regulator and a plurality of different control signals;
- selecting a control signal based on relative magnitudes of the speed control signal and the plurality of different control signals to output to the motor;
- and
- limiting an acceleration of the motor by driving the motor with control circuitry that limits the acceleration of the motor according to the selected control signal.
A system comprising:
- an electric motor;
- controller circuitry configured to receive a plurality of reference signals and a plurality of output signals from the electric motor, and further configured to drive the electric motor according to a control signal that limits an acceleration of the electric motor, wherein the controller circuitry comprises a plurality of regulators and an acceleration estimator,
- wherein the acceleration estimator is configured to:
- receive an output speed signal of an output speed of the electric motor detected by a speed sensor;
- determine an acceleration estimate based on the output speed signal;
- determine that the acceleration estimate is outside a preset range;
- and
- calculate a speed set point based on a maximum acceleration value from the preset range;
- and
- wherein a speed regulator from the plurality of regulators is configured to:
- receive a speed error signal based on the speed set point and the output speed;
- and
- output a speed control signal based on the speed error signal;
- and
- a minimum selector module configured to:
- receive the speed control signal and a plurality of different control signals;
- compare the speed control signal and the plurality of different control signals;
- and
- select the control signal based on relative magnitudes of the speed control signal and the plurality of different control signals to output to the electric motor.
An acceleration estimator of a motor, comprising:
- a first limiting regulator configured to output values in a preset range, wherein the first limiting regulator:
- receives an error signal representing a difference between an output speed of an electric motor detected by a speed sensor and a speed set point;
- and
- outputs an acceleration estimate, wherein the acceleration estimate is limited to the preset range;
- a second limiting regulator configured to output an override signal;
- and
- an integrator that receives the acceleration estimate from the first limiting regulator and outputs the speed set point,
- wherein the motor is controlled by control circuitry using a control signal derived from combining the override signal with a signal selected from a speed control signal from a speed regulator and a plurality of different control signals, and
- wherein the control signal limits an acceleration of the motor.
Dependencies are inferred from the claim text.