ELECTRIC APPARATUS AND CONTROL METHOD THEREFOR

• US 20190329573A1
• Filed: 04/22/2019
• Published: 10/31/2019
• Est. Priority Date: 04/27/2018
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kiyama, Kota, Suzuki, Yuichiro, Iwai, Isao, Tanami, Haruhiko
• Granted Patent: US 10,946,679 B2
• Time in Patent Office: Days
• CPC Class Codes: B41J 19/202 Drive control means for carriage movement
• CPC Class Codes: B41J 19/205 Position or speed detectors therefor
• CPC Class Codes: B41J 19/207 Encoding along a bar
• CPC Class Codes: B41J 25/006 for oscillating, e.g. page-width print heads provided with counter-balancing means or shock absorbers
• CPC Class Codes: H02P 23/0004 Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
• CPC Class Codes: H02P 23/04 specially adapted for damping motor oscillations, e.g. for reducing hunting
• CPC Class Codes: H02P 23/20 Controlling the acceleration or deceleration
• CPC Class Codes: H02P 7/00 Arrangements for regulating or controlling the speed or torque of electric DC motors

Abstract

According to an embodiment of the present invention, an electric apparatus for controlling movement of a target object by performing first and second feedback controls, based on a detection signal obtained from detecting the movement of the target object, generates an operation quantity on the target object based on first and second operation quantities for the second feedback control if one of a predetermined target value and an estimated first state quantity of the target object is larger than a first threshold value, and generates the operation quantity on the target object using only the first operation quantity out of the first and the second operation quantities if one of the target value and the first state quantity of the target object is smaller than the first threshold value.

Claims

1. An electric apparatus for controlling movement of a target object, comprising:

a detection unit configured to detect the movement of the target object;

a first estimation unit configured to estimate, based on a detection signal output from the detection unit, a control quantity for performing first feedback control for the target object at a first period;

a second estimation unit configured to estimate, based on the detection signal output from the detection unit, a first state quantity of the target object and a second state quantity obtained by time differentiation of the first state quantity in order to perform second feedback control for the target object at a second period shorter than the first period;

a first generation unit configured to generate a first operation quantity for the first feedback control based on the control quantity estimated by the first estimation unit;

a second generation unit configured to generate a second operation quantity for the second feedback control based on the first state quantity and the second state quantity estimated by the second estimation unit; and

a synthesizing unit configured to generate an operation quantity on the target object,

wherein if one of a predetermined target value and the first state quantity of the target object estimated by the second estimation unit is larger than a first threshold value, the synthesizing unit generates the operation quantity on the target object based on the first operation quantity and the second operation quantity, and if one of the target value and the first state quantity of the target object is smaller than the first threshold value, the synthesizing unit generates the operation quantity on the target object using only the first operation quantity out of the first operation quantity and the second operation quantity.

2. The apparatus according to claim 1, wherein the second estimation unit sets an estimation frequency of the second state quantity when the first state quantity of the target object is smaller than a second threshold value larger than the first threshold value to be higher than an estimation frequency of the second state quantity when the first state quantity of the target object is larger than the second threshold value.

3. The apparatus according to claim 2, wherein if one of the target value and the first state quantity of the target object is smaller than the first threshold value, an output from the second generation unit becomes zero, and the synthesizing unit generates the operation quantity on the target object using only the first operation quantity out of the first operation quantity and the second operation quantity.

4. The apparatus according to claim 3, wherein if one of the target value and the first state quantity of the target object is smaller than the first threshold value, the output from the second generation unit becomes zero by not generating the second operation quantity by the second generation unit, and the movement of the target object is controlled using only the first feedback control out of the first feedback control and the second feedback control.

5. The apparatus according to claim 2, wherein a combination of the first state quantity and the second state quantity comprises a combination of a velocity and an acceleration of the target object.

6. The apparatus according to claim 2, wherein

the electric apparatus comprises a printing apparatus configured to print on a print medium by a printhead by reciprocally moving a carriage mounted with the printhead, and

the target object comprises the carriage.

7. The apparatus according to claim 6, wherein

the first state quantity comprises a velocity of the carriage, and

the second state quantity comprises an acceleration of the carriage.

8. The apparatus according to claim 6, wherein

the detection unit includes an encoder sensor configured to detect a position of the carriage, and

the second estimation unit estimates a velocity of the carriage by measuring an edge interval of an encoder signal pulse output from the encoder sensor.

9. The apparatus according to claim 8, wherein if the velocity of the carriage is lower than the second threshold value, the second estimation unit estimates the velocity of the carriage using a leading edge and a trailing edge of each of an A-phase encoder signal pulse and a B-phase encoder signal pulse, and if the velocity of the carriage is higher than the second threshold value, the second estimation unit estimates the velocity of the carriage using one edge of one of the A-phase encoder signal pulse and the B-phase encoder signal pulse.

10. The apparatus according to claim 1, wherein

the first generation unit is implemented by executing a program by a processor, and

the first estimation unit, the second estimation unit, the second generation unit, and the synthesizing unit are implemented by an ASIC.

11. The apparatus according to claim 1, wherein

the electric apparatus comprises one of a scanner apparatus configured to read an image of an original by a scanner unit mounted with a CIS or a CCD sensor by moving the scanner unit, and a multi-function printer obtained by providing the scanner apparatus in a printing apparatus for printing on a print medium by a printhead by reciprocally moving a carriage mounted with the printhead,

the target object comprises the scanner unit.

12. A control method for an electric apparatus for controlling movement of a target object, comprising:

detecting the movement of the target object;

estimating, based on a detection signal acquired in the detecting, a control quantity for performing first feedback control for the target object at a first period;

estimating, based on the detection signal acquired in the detecting, a first state quantity of the target object and a second state quantity obtained by time differentiation of the first state quantity in order to perform second feedback control for the target object at a second period shorter than the first period;

generating a first operation quantity for the first feedback control based on the estimated control quantity;

generating a second operation quantity for the second feedback control based on the estimated first state quantity and the estimated second state quantity; and

generating an operation quantity on the target object,

wherein in the generating the operation quantity, if one of a predetermined target value and the estimated first state quantity of the target object is larger than a first threshold value, the operation quantity on the target object is generated based on the first operation quantity and the second operation quantity, and if one of the target value and the first state quantity of the target object is smaller than the first threshold value, the operation quantity on the target object is generated using only the first operation quantity out of the first operation quantity and the second operation quantity.

13. The method according to claim 12, wherein in the estimating the first state quantity and the second state quantity, an estimation frequency of the second state quantity when the first state quantity of the target object is smaller than a second threshold value larger than the first threshold value is set to be higher than an estimation frequency of the second state quantity when the first state quantity of the target object is larger than the second threshold value.

14. The method according to claim 13, wherein if one of the target value and the first state quantity of the target object is smaller than the first threshold value, an output in the generating the second operation quantity becomes zero, and the operation quantity on the target object is generated using only the first operation quantity out of the first operation quantity and the second operation quantity.

15. The method according to claim 14, wherein if one of the target value and the first state quantity of the target object is smaller than the first threshold value, the output in the generating the second operation quantity becomes zero by not generating the second operation quantity, and the movement of the target object is controlled using only the first feedback control out of the first feedback control and the second feedback control.

16. The method according to claim 13, wherein a combination of the first state quantity and the second state quantity comprises a combination of a velocity and an acceleration of the target object.