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 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 device includes a unit including a cylinder and a piston, a subject support unit that moves in accordance with relative movement of the cylinder and the piston, a control board that generates a control signal including a first pulse width based on an operation signal input by a user operation, and an oil amount adjustment unit that adjusts the amount of oil contained in the cylinder based on the first pulse width, wherein the control board determines a value of a gain based on a deviation, calculates a second pulse width based on the deviation and the determined gain value, and generates a control signal including the second pulse width when the next operation signal is input, and the oil amount adjustment unit adjusts the amount of oil in the cylinder based on the second pulse width.

A device includes a unit including a cylinder and a piston, a subject support unit that moves in accordance with relative movement of the cylinder and the piston, a control board that generates a control signal including a first pulse width based on an operation signal input by a user operation, and an oil amount adjustment unit that adjusts the amount of oil contained in the cylinder based on the first pulse width, wherein the control board determines a value of a gain based on a deviation, calculates a second pulse width based on the deviation and the determined gain value, and generates a control signal including the second pulse width when the next operation signal is input, and the oil amount adjustment unit adjusts the amount of oil in the cylinder based on the second pulse width.