IP Library Granted Patent US 8,080,953
Granted Patent B2
US 8,080,953 · App. 12/182,157 · Granted Dec 20, 2011

Motor control method and device

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Quick Facts
Patent No.
US 8,080,953
App. No.
12/182,157
Granted
Dec 20, 2011
Kind
B2
Abstract

A control device includes a drive control unit that performs control for driving the electromagnetic coil, and a regeneration control unit that performs control for regenerating power from the electromagnetic coil. The drive control unit includes an excitation interval setting unit that sets an excitation interval and a non-excitation interval such that voltage is applied to the electromagnetic coil during the excitation interval while not applied to the electromagnetic coil during the non-excitation interval. The excitation interval has a symmetrical shape whose center corresponds to a π/2 phase point of the induced voltage waveform, and the non-excitation interval has a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform. The regeneration control unit includes a regeneration interval setting unit that sets a regeneration interval and a non-regeneration interval such that power is regenerated from the electromagnetic coil during the regeneration interval while not regenerated from the electromagnetic coil during the non-regeneration interval. The regeneration interval has a symmetrical shape whose center corresponds to the π/2 phase point of the induced voltage waveform, and the non-regeneration interval has a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform.

Claims (50)

1. A control device for controlling an electric motor having an electromagnetic coil and a permanent magnet, comprising:

a drive control unit that performs control for driving the electromagnetic coil; and

a regeneration control unit that performs control for regenerating power from the electromagnetic coil,

wherein an induced voltage is induced at the electromagnetic coil responsive to movement of the permanent magnet, the induced voltage having a waveform whose polarity is reversed at a π phase point of the waveform,

the drive control unit includes an excitation interval setting unit that sets an excitation interval and a non-excitation interval such that voltage is applied to the electromagnetic coil during the excitation interval while not applied to the electromagnetic coil during the non-excitation interval, the excitation interval having a symmetrical shape whose center corresponds to a π/2 phase point of the induced voltage waveform, the non-excitation interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform,

a multiplication unit that calculates a multiplication value by multiplying a signal value of a change signal indicating changes over time and a control value which can be set at a desired value within a specific range;

a PWM signal generating unit that generates PWM signals having a pulse width according to the multiplication value by performing PWM control on the multiplication value;

a mask circuit that generates drive signals of the electric motor by masking the PWM signal at the non-excitation interval; and

an adjustment unit that adjusts both the control value and partition between the excitation interval and the non-excitation interval according to an output power request for the electric motor,

the regeneration control unit includes a regeneration interval setting unit that sets a regeneration interval and a non-regeneration interval such that power is regenerated from the electromagnetic coil during the regeneration interval while not regenerated from the electromagnetic coil during the non-regeneration interval, the regeneration interval having a symmetrical shape whose center corresponds to the π/2 phase point of the induced voltage waveform, the non-regeneration interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform.

2. The control device in accordance with claim 1 , wherein

the excitation interval setting unit and the regeneration interval setting unit are capable of independently changing partition between the excitation interval and the non-excitation interval, and partition between the regeneration interval and the non-regeneration interval.

3. The control device in accordance with claim 1 , wherein

when the drive control unit and the regeneration control unit are not performing either the drive control or the regeneration control of the electric motor, the drive control unit and the regeneration control unit maintain the electromagnetic coil in a high impedance state.

4. A method of controlling an electric motor having an electromagnetic coil and a permanent magnet, comprising:

performing control for driving the electromagnetic coil; and

performing control for regenerating power from the electromagnetic coil,

wherein an induced voltage is induced at the electromagnetic coil responsive to movement of the permanent magnet, the induced voltage having a waveform whose polarity is reversed at a π phase point of the waveform,

the drive control step includes setting an excitation interval and a non-excitation interval such that voltage is applied to the electromagnetic coil during the excitation interval while not applied to the electromagnetic coil during the non-excitation interval, the excitation interval having a symmetrical shape whose center corresponds to a π/2 phase point of the induced voltage waveform, the non-excitation interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform,

calculating a multiplication value by multiplying a signal value of a change signal indicating changes over time and a control value which can be set at a desired value within a specific range;

generating PWM signals having a pulse width according to the multiplication value by performing PWM control on the multiplication value;

generating drive signals of the electric motor by masking the PWM signal at the non-excitation interval; and

adjusting both the control value and partition between the excitation interval and the non-excitation interval according to an output power request for the electric motor,

the regeneration control step includes setting a regeneration interval and a non-regeneration interval such that power is regenerated from the electromagnetic coil during the regeneration interval while not regenerated from the electromagnetic coil during the non-regeneration interval, the regeneration interval having a symmetrical shape whose center corresponds to the π/2 phase point of the induced voltage waveform, the non-regeneration interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform.

5. A robot comprising:

an electric motor having an electromagnetic coil and a permanent magnet; and

a control device for controlling the electric motor,

wherein the control device includes:

a drive control unit that performs control for driving the electromagnetic coil; and

a regeneration control unit that performs control for regenerating power from the electromagnetic coil,

wherein an induced voltage is induced at the electromagnetic coil responsive to movement of the permanent magnet, the induced voltage having a waveform whose polarity is reversed at a π phase point of the waveform,

the drive control unit includes an excitation interval setting unit that sets an excitation interval and a non-excitation interval such that voltage is applied to the electromagnetic coil during the excitation interval while not applied to the electromagnetic coil during the non-excitation interval, the excitation interval having a symmetrical shape whose center corresponds to a π/2 phase point of the induced voltage waveform, the non-excitation interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform,

a multiplication unit that calculates a multiplication value by multiplying a signal value of a change signal indicating changes over time and a control value which can be set at a desired value within a specific range;

a PWM signal generating unit that generates PWM signals having a pulse width according to the multiplication value by performing PWM control on the multiplication value;

a mask circuit that generates drive signals of the electric motor by masking the PWM signal at the non-excitation interval; and

an adjustment unit that adjusts both the control value and partition between the excitation interval and the non-excitation interval according to an output power request for the electric motor,

the regeneration control unit includes a regeneration interval setting unit that sets a regeneration interval and a non-regeneration interval such that power is regenerated from the electromagnetic coil during the regeneration interval while not regenerated from the electromagnetic coil during the non-regeneration interval, the regeneration interval having a symmetrical shape whose center corresponds to the π/2 phase point of the induced voltage waveform, the non-regeneration interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform.

6. A moving body comprising:

an electric motor having an electromagnetic coil and a permanent magnet; and

a control device for controlling the electric motor,

wherein the control device includes:

a drive control unit that performs control for driving the electromagnetic coil; and

a regeneration control unit that performs control for regenerating power from the electromagnetic coil,

wherein an induced voltage is induced at the electromagnetic coil responsive to movement of the permanent magnet, the induced voltage having a waveform whose polarity is reversed at a π phase point of the waveform,

the drive control unit includes an excitation interval setting unit that sets an excitation interval and a non-excitation interval such that voltage is applied to the electromagnetic coil during the excitation interval while not applied to the electromagnetic coil during the non-excitation interval, the excitation interval having a symmetrical shape whose center corresponds to a π/2 phase point of the induced voltage waveform, the non-excitation interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform,

a multiplication unit that calculates a multiplication value by multiplying a signal value of a change signal indicating changes over time and a control value which can be set at a desired value within a specific range;

a PWM signal generating unit that generates PWM signals having a pulse width according to the multiplication value by performing PWM control on the multiplication value;

a mask circuit that generates drive signals of the electric motor by masking the PWM signal at the non-excitation interval; and

an adjustment unit that adjusts both the control value and partition between the excitation interval and the non-excitation interval according to an output power request for the electric motor,

the regeneration control unit includes a regeneration interval setting unit that sets a regeneration interval and a non-regeneration interval such that power is regenerated from the electromagnetic coil during the regeneration interval while not regenerated from the electromagnetic coil during the non-regeneration interval, the regeneration interval having a symmetrical shape whose center corresponds to the π/2 phase point of the induced voltage waveform, the non-regeneration interval having a symmetrical shape whose center corresponds to the π phase point of the induced voltage waveform.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 14, 2016
From: SEIKO EPSON CORPORATION
To: GODO KAISHA IP BRIDGE 1
Reel/Frame 040030/0262 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 30, 2008
From: TAKEUCHI, KESATOSHI
To: SEIKO EPSON CORPORATION
Reel/Frame 021310/0642 →