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AssigneeSTMicroelectronics (Grand Ouest) SAS
InventorsEmmanuel Langouet, Samuel Rousselin
Estimating the term…
A stepper motor is driven according to step driving modes including a full-step driving mode, a half-step driving mode and micro-stepping modes. The stepper motor may also be driven in an acceleration phase. A method of controlling the stepper motor includes controlling the current step driving mode of the motor by a processing unit. During the acceleration phase of the stepper motor and the stepper motor being in driven in a current step driving mode other than the full-step driving mode, the processing unit tests, after each speed increase, if a remaining computing power of the processing unit is sufficient for control of the stepper motor to remain in the current step driving mode, and if not the processing unit, in presence of a first switching condition, switches control of the stepper motor to the driving mode having the closest coarser step.
A method for driving a stepper motor, comprising:
A device for driving a stepper motor configured to be driven in step driving modes including a full-step driving mode, a half-step driving mode and micro-stepping modes, and the stepper motor configured to be driven in an acceleration phase, the device comprising a processing unit configured to control a current step driving mode of the motor and, in response to the stepper motor being driven in the acceleration phase and the current step driving mode being other than the full-step driving mode, the processing unit configured to determine, after each speed increase of the motor in the acceleration phase, if a remaining computing power of the processing unit is sufficient for continuing to control the stepper motor in said current step driving mode and, if the remaining computing power is not sufficient, to switch control of the stepper motor to a closest coarser step driving mode in presence of a first switching condition including a correspondence of a current position of the stepper motor in said current step driving mode with a position defined in said step driving mode having the closest coarser step.
A device for driving a stepper motor configured to be driven in step driving modes including a full-step driving mode, a half-step driving mode and micro-stepping modes, and the stepper motor configured to be driven in an acceleration phase, the device comprising a processing unit configured to control a current step driving mode of the motor (SM) and, in response to the stepper motor being driven in the acceleration phase and the current ep driving mode being other than the full-step driving mode, the processing unit configured to determine, after each speed increase of the motor in the acceleration phase, if a remaining computing power of the processing unit is sufficient for continuing to control the stepper motor in said current step driving mode and, if the remaining computing power is not sufficient, to switch control of the stepper motor to a closest coarser step driving mode in presence of a first switching condition, wherein the processing unit is further configured to evaluate a computing time needed to determine control parameters to be applied to the stepper motor in order for the stepper motor to reach a next position in said current step driving mode, and is configured to determine a switching time required by the stepper motor to switch to said next position based on a current speed of the stepper motor, and wherein said processing unit is configured to determine said remaining computing power is sufficient to remain in said current step driving mode if said switching time is greater than or equal to said computing time plus a first margin.
Dependencies are inferred from the claim text.