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US 9,612,600 B2Granted
Controller of linear motion device and control method of the same
AssigneeAsahi Kasei Microdevices Corporation
InventorTakashi Fukushima
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to controllers of linear motion devices and control methods of the same, in particular, to a controller of a linear motion device and a control method of the same capable of controlling the position of the linear motion device accurately, in a case where a misalignment of the mounting position of a magnetic sensor or a magnetizing variation of a magnet occurs, or in a case where a magnetic field detected by the magnetic sensor receives an interference of the magnetic field generated by a driving coil of the linear motion device.
Claims13
A controller of a linear motion device including a magnet attached to a moving body and disposed adjacent to a driving coil, the controller comprising:
- a magnetic field sensor configured to detect a magnetic field generated by the magnet and output a detection position signal value corresponding to a value of the magnetic field;
- a calibration operation circuit configured to obtain the detection position signal value and generate a detection position operation signal value;
- a device position instruction signal generation circuit configured to output a target position signal value for instructing a target position to which the linear motion device is to move;
- a leak magnetic field correction circuit configured to correct the target position signal value and output a target correction position signal value;
- a PID control circuit configured to output a control signal based on the detection position operation signal value and the target correction position signal value;
- and
- an output driver configured to supply a driving current to the driving coil to move the moving body to the target position based on the control signal,
- wherein the leak magnetic field correction circuit is configured to correct the target position signal value based on the control signal and a value of a leak magnetic field caused by the driving coil, and the value of the leak magnetic is calculated based on a difference between the detection position signal value when an electric power is not supplied to the driving coil and the detection position signal value when the electric power is supplied to the driving coil.
5 more elements
A calibration method of a controller of a linear motion device, the linear motion device comprising a driving coil configured to move the linear motion device;
- a magnetic field sensor configured to detect a magnetic field of the magnet, the calibration method comprising:
- supplying a drive current to the driving coil to move the linear motion device to a first position;
- obtaining in the first position a detection position signal value corresponding to a value of the magnetic field that has been detected by the magnetic field sensor, when an electric power is supplied to the driving coil;
- obtaining in the first position the detection position signal value corresponding to the value of the magnetic field that has been detected by the magnetic field sensor, when supplying the electric power to the driving coil is stopped;
- supplying the drive current to the driving coil to move the linear motion device to a second position;
- obtaining in the second position the detection position signal value corresponding to the value of the magnetic field that has been detected by the magnetic field sensor, when supplying the electric power to the driving coil is stopped;
- and
- correcting a target position signal value for instructing a target position to which the linear motion device is to move by use of a value of a leak magnetic field that has been calculated based on
- the detection position signal value corresponding to a value of the magnetic field that has been detected by the magnetic field sensor, when an electric power is supplied to the driving coil in the first position,
- the detection position signal value corresponding to the value of the magnetic field that has been detected by the magnetic field sensor, when supplying the electric power to the driving coil is stopped in the first position, and
- the detection position signal value corresponding to the value of the magnetic field that has been detected by the magnetic field sensor, when supplying the electric power to the driving coil is stopped.
8 more elements
A controller of a linear motion device, the controller comprising:
- a device position instruction signal generation circuit configured to output a target position signal value for instructing a target position to which the linear motion device including a magnet attached to a moving body is to move;
- a leak magnetic field correction circuit configured to correct a detection position signal value obtained by detecting a magnetic field generated by the magnet;
- an output driver configured to supply a driving current to a driving coil based on the detection position signal value that has been corrected by the leak magnetic field correction circuit and the target position signal value,
- wherein the leak magnetic field correction circuit is configured to correct the detection position signal value based on a value of a leak magnetic field of the driving coil, and
- wherein the value of the leak magnetic field is calculated based on a difference between the detection position signal value when an electric power is not supplied to the driving coil and the detection position signal value when the electric power is supplied to the driving coil.
2 more elements
Dependencies are inferred from the claim text.