WO2008069205A1

WO2008069205A1 - Motor drive control apparatus, electrically driven assist apparatus, and responsiveness feedback control method

Info

Publication number: WO2008069205A1
Application number: PCT/JP2007/073402
Authority: WO
Inventors: Mitsuyuki Wakabayashi; Hiroshi Ochiai
Original assignee: Nifco, Inc.
Priority date: 2006-12-05
Filing date: 2007-12-04
Publication date: 2008-06-12
Also published as: JP4881138B2; TWI382649B; TW200836471A; JP2008141923A

Abstract

A motor drive control apparatus, an electrically driven assist apparatus and a responsiveness feedback control method wherein even if a target rotational speed oscillates during a low speed operation, the occurrence of hunting of the rotational speed of a motor can be suppressed, while the reduction of speed responsiveness being suppressed. A rotational speed determining part (92) determines the rotational speed of a motor (40). A target rotational speed acquiring part (90) acquires a target rotational speed of the motor (40). A gain coefficient deriving part (94) derives a gain coefficient with which the adjustment amount of the rotational speed of the motor (40) is amplified within such a range that there will occur no overshoot that the rotational speed of the motor (40) exceeds the target rotational speed. At this moment, the gain coefficient is derived in such a manner that the higher the determined rotational speed is, the larger value the derived gain coefficient exhibits. A PID control part (96) performs a feedback control of the rotational speed of the motor (40) based on both the deviation of the determined rotational speed from the acquired target rotational speed and the derived gain coefficient.

Description

Specification

Motor drive control device, electric assist device, and responsive feedback control method

Technical field

TECHNICAL FIELD [0001] The present invention relates to a motor drive control device, an electric assist device, and a responsive feedback control method, and in particular, a motor drive that performs feedback control of the rotation speed of a motor (specifically, the rotation speed of a rotor of a motor). The present invention relates to a control device, an electric assist device including the motor drive control device, and a responsive feedback control method.

Background art

[0002] A hanging cabinet provided in a kitchen or the like for storing articles such as tableware and cooking utensils is generally provided at a high position such as an upper surface of a sink. For this reason, hanging cabinets were inconvenient for loading and unloading heavy and large items.

[0003] Therefore, as a technique for facilitating the taking in and out of articles to and from the hanging cabinet, Patent Document 1 discloses an inner box that is moved up and down by an electric lifting mechanism on an outer box that is attached to the wall of the upper surface of a kitchen or the like. An electric elevating hanging cupboard having a configuration in which is provided is described. In this electric lifting / lowering cabinet, when an article is taken in / out, the inner box is lowered by operating a switch provided in the operation unit, so that the article can be easily taken in / out.

[0004] Note that the description in the above Japanese Patent Laid-Open No. 2005-21298 is a part of the description in this specification.

Patent Document 1: Japanese Unexamined Patent Publication No. 2005-21298

Disclosure of the invention

Problems to be solved by the invention

[0005] By the way, the electric lifting / lowering cabinet described in Patent Document 1 has a position where the inner box can be lowered to a position where an article can be taken in and out, or can be stored in the outer box, when the raising / lowering speed of the inner box is reduced. It took a long time to raise the inner box, and the usability was bad. On the other hand, if the raising / lowering speed of the inner box is increased, the usability is improved, but the raising / lowering distance of the inner box per unit time becomes longer.For example, when an object is sandwiched between the inner box and the outer box. , The ascending / descending distance by which the inner box moves up and down becomes longer until the operator instructs the operation unit to stop the lifting operation of the inner box.

[0006] Therefore, in the case of applying the electric lifting cabinet described in Patent Document 1, the actual situation is that the lifting speed must be reduced! /.

[0007] Therefore, for example, a grip portion such as a grip bar is provided in the inner box, and the direction and magnitude of strain generated in the grip bar when a user applies a force to raise and lower the inner box with respect to the grip bar. Is detected, and the target rotation speed of the motor is obtained according to the detection result, and feedback control is performed to control the motor rotation speed so that it matches the target rotation speed. An electric hanging cabinet equipped with an electric assist device that assists the user in raising and lowering the inner box by rotating the motor at a corresponding rotation speed can be considered.

Incidentally, PID control is known as one type of such feedback control. This PID control is feedback control that combines P control (proportional control), I control (integral control), and D control (differential control). For example, the deviation (speed difference) of the motor rotation speed from the target rotation speed, An integral value obtained by time-integrating the deviation and a differential value obtained by time-differentiating the deviation are obtained, the obtained deviation, the integral value, and the differential value are added, and a predetermined gain coefficient is obtained for the value obtained by the addition. And the rotational speed of the motor is controlled based on the value obtained by the multiplication.

In this PID control, when the gain coefficient is set to a relatively large value, the adjustment amount per unit time of the rotation speed of the motor corresponding to the deviation is large, so that as shown in FIG. 13A as an example, the target rotation When the speed is changed, the time required for the motor speed to reach the target speed is short, and the speed response is high.

However, in this case, as shown in FIG. 13B as an example, when the target rotational speed vibrates, there is a problem that hunting may occur in the rotational speed of the motor along with the vibration. It was.

[0011] For example, the rotational speed of the motor is controlled by electric suspension rack force PID control equipped with an electric assist device that assists the user in raising and lowering the inner box, and a relatively large value is set for the gain coefficient. Suppose that it was done. In this case, the user However, if you try to lift the inner box slowly by adjusting the force applied to the inner box, the amount of adjustment of the rotation speed of the motor according to the strain amount of the grip bar is large, so the inner box will move as the motor rotates. The raising / lowering speed of raising / lowering may be faster than the raising / lowering speed of the user's hand raising / lowering the grip bar, and the hand may be left behind.

[0012] As described above, when the hand is left behind, the amount of distortion of the grip bar is reduced, the target rotational speed is lowered, and the raising / lowering speed of the inner box is also lowered. Then, when the user's hand catches up with the grip bar due to the lowering of the lifting speed of the inner box, the target rotational speed increases as the strain amount of the grip bar increases, and the lifting speed of the inner box increases. As a result of the speed being raised again faster than the lifting speed and the hands being left behind the grip bar repeatedly, hunting occurs in the rotational speed of the motor along with the vibration of the target rotational speed.

[0013] Then, in the electric assist device that assists the user's operation with respect to the assist object by the driving force of the motor, if the hunting occurs in the rotation speed of the motor in association with the vibration of the target rotation speed during the low-speed operation, the assist object It is not possible to smoothly assist the user's actions against.

On the other hand, in the PID control, when the gain coefficient is set to a relatively small value, the adjustment amount per unit time of the rotation speed of the motor according to the deviation is small. Even if the target rotational speed vibrates, it is difficult for hunting to occur in the rotational speed of the motor.

However, in this case, as shown in FIG. 14A as an example, when the target rotational speed is changed, the time required for the motor rotational speed to reach the target rotational speed is increased, and the speed response is increased. There was a problem that the property was low.

[0016] The present invention has been made to solve the above problems, and hunting the rotational speed of the motor even when the target rotational speed vibrates during low-speed operation while suppressing a decrease in speed responsiveness. An object of the present invention is to provide a motor drive control device, an electric assist device, and a responsive feedback control method that can suppress the occurrence of the above.

Means for solving the problem

In order to achieve the above object, the invention according to claim 1 detects the rotational speed of the motor. A detection unit configured to acquire a target rotational speed of the motor, and a rotational speed of the motor to be matched with the target rotational speed according to a deviation of the rotational speed of the motor with respect to the target rotational speed. When performing feedback control to control, a gain coefficient for amplifying an adjustment amount of the rotation speed of the motor within a range in which an overshoot in which the rotation speed of the motor exceeds the target rotation speed is not generated, A derivation unit that derives a larger value as the rotation speed detected by the step increases, a deviation of the rotation speed detected by the detection unit from the target rotation speed acquired by the acquisition unit, and the A control unit that performs the feed knock control based on the gain coefficient derived by the deriving unit.

[0018] According to the invention of claim 1, the derivation unit performs feedback control for controlling the motor rotation speed to match the target rotation speed in accordance with the deviation of the motor rotation speed from the target rotation speed. When detecting, the gain coefficient that amplifies the adjustment amount of the motor rotation speed is within the range where the motor rotation speed does not cause an overshoot that exceeds the target rotation speed. It is derived so that the higher the rotation speed detected by the above, the larger the value.

In the present invention, the control unit derives the deviation of the rotational speed detected by the detection unit from the target rotational speed acquired by the acquisition unit that acquires the target rotational speed of the motor, and the derivation unit. Feedback control is performed based on the gain coefficient.

[0020] As a result, when the rotational speed of the motor is relatively low, the derived gain coefficient is relatively small. Since the adjustment amount per unit time of the rotational speed of the motor is small, the target rotational speed vibrates. Even so, it is possible to suppress the occurrence of hunting in the rotational speed of the motor. In addition, the gain coefficient that is derived as the motor rotational speed increases and the amount of adjustment per unit time of the motor rotational speed also increases, so that a decrease in speed response can be suppressed.

As described above, according to the first aspect of the invention, the rotational speed of the motor is detected, the target rotational speed of the motor is acquired, and the motor is controlled according to the deviation of the rotational speed of the motor from the target rotational speed. When performing feedback control that controls the rotational speed of the motor to match the target rotational speed, overshoot that causes the motor rotational speed to exceed the target rotational speed A gain coefficient that amplifies the adjustment amount of the motor rotation speed within a range that does not occur is derived so that the gain coefficient increases as the detected rotation speed increases, and the deviation of the detected rotation speed from the acquired target rotation speed is derived. And / or feedback control based on the derived gain coefficient, so that even if the target rotational speed oscillates during low-speed operation, the motor rotational speed is controlled while suppressing a decrease in speed responsiveness. Use force S to suppress hunting.

[0022] Note that, as described in claim 2, the control unit according to the present invention includes the deviation, an integral value obtained by time-integrating the deviation, a differential value obtained by time-differentiating the deviation, and the derivation as the feedback control. PID control may be performed based on the gain coefficient derived by the unit.

[0023] In addition, as described in claim 3, the control unit of the present invention adds the deviation, the integral value, and the minute value, and multiplies the gain coefficient by the value obtained by the addition. The PID control may be performed based on the value obtained by the multiplication.

[0024] On the other hand, in order to achieve the above object, the electric assist device according to claim 4 includes the motor drive control device according to any one of claims 1 to 3 and the motor drive control device. A motor that is controlled and drives the assist target.

[0025] Therefore, the electric assist device according to claim 4 operates in the same manner as the invention according to claim 1. Therefore, similarly to the invention according to claim 1, while suppressing a decrease in speed responsiveness, Even if the target rotational speed vibrates during low-speed operation, hunting can be suppressed from occurring in the motor rotational speed. As a result, the user's operation on the assist target can be assisted smoothly.

[0026] On the other hand, in order to achieve the above object, the responsive feedback control method according to claim 5 detects the rotational speed of the motor, acquires the target rotational speed of the motor, and obtains the motor with respect to the target rotational speed. When performing feedback control for controlling the motor rotational speed to match the target rotational speed according to the rotational speed deviation, an overshoot occurs in which the motor rotational speed exceeds the target rotational speed. A gain coefficient that amplifies the adjustment amount of the rotation speed of the motor within a range that is not to be derived is derived so that the gain coefficient increases as the detected rotation speed increases, and the acquired target rotation speed is derived. The feedback control is performed based on the detected deviation of the rotational speed with respect to the degree and the derived gain coefficient.

[0027] Therefore, according to the responsive feedback control method according to claim 5, since it operates in the same manner as the invention according to claim 1, a decrease in speed responsiveness is suppressed as in the invention according to claim 1. However, it is possible to suppress the occurrence of hunting in the rotational speed of the motor even when the target rotational speed vibrates during low speed operation.

The invention's effect

[0028] As described above, according to the present invention, the rotational speed of the motor is detected, the target rotational speed of the motor is obtained, and the motor rotational speed is deviated according to the deviation of the rotational speed of the motor from the target rotational speed. When feedback control is performed to control the rotational speed so that it matches the target rotational speed, the amount of adjustment of the rotational speed of the motor must be adjusted within a range where the motor rotational speed does not cause an overshoot that exceeds the target rotational speed. The gain coefficient to be amplified is derived so as to increase as the detected rotational speed increases, and the deviation of the detected rotational speed with respect to the acquired target rotational speed and the feedback control based on the derived gain coefficient! Therefore, hunting occurs in the motor rotation speed even if the target rotation speed vibrates during low-speed operation while suppressing the decrease in speed responsiveness. Door can suppress this and force S, and has an excellent effect that.

Brief Description of Drawings

FIG. 1 is a perspective view showing a configuration of an electric hanging cabinet in a state where a cabinet according to an embodiment is housed.

FIG. 2 is a perspective view showing a configuration of an electric hanging cabinet in a state where the cabinet according to the embodiment is lowered.

FIG. 3 is an enlarged view showing a detailed configuration of the gear train according to the embodiment.

FIG. 4A is a cross-sectional view of a gripping part according to an embodiment.

FIG. 4B is a longitudinal sectional view of the gripping part according to the embodiment.

FIG. 5 is a block diagram showing the main configuration of the electrical system of the electric hanging cabinet according to the embodiment.

FIG. 6 is a schematic diagram showing an example of a data structure of a potential difference target rotation speed conversion table according to the embodiment. FIG. 7] is a block diagram showing a functional configuration of the microcomputer according to the embodiment.

FIG. 8 is a graph showing the relationship between changes in the rotational speed of the motor for each gain coefficient.

FIG. 9A] is a diagram showing an operation when the electric hanging cabinet according to the embodiment is lowered.

[FIG. 9B] FIG. 9B is a diagram showing an operation when the cabinet of the electric hanging cabinet according to the embodiment is lowered.

[FIG. 9C] It is a diagram showing an operation when the cabinet of the electric hanging cupboard according to the embodiment is lowered.

FIG. 10A] is a diagram showing an operation when storing the cabinet of the electric hanging cupboard according to the embodiment.

FIG. 10B] is a diagram showing an operation when the cabinet of the electric hanging cupboard according to the embodiment is stored.

FIG. 10C] is a diagram showing an operation when storing the cabinet of the electric hanging cupboard according to the embodiment.

FIG. 11 is a flowchart showing a process flow of the drive control program according to the embodiment.

12A] A graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by the PID control according to the embodiment.

12B] A graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by the PID control according to the embodiment.

FIG. 13A is a graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by conventional PID control.

FIG. 13B is a graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by conventional PID control.

FIG. 14A is a graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by conventional PID control.

FIG. 14B is a graph showing an example of a change in the rotation speed of the motor when the rotation speed of the motor is controlled by conventional PID control. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the case where the present invention is applied to an electric hanging cabinet will be described.

[0031] FIGS. 1 and 2 show an electric hanging cabinet 10 according to an embodiment of the present invention.

[0032] As an example, this electric hanging cabinet 10 is used for ceiling installation used in a system kitchen. The electric hanging cabinet 10 includes a box-shaped cabinet 12, and the cabinet 12 can store tableware and the like. The cabinet 12 can be stored in a box-shaped storage unit 14 whose front side and rear side are open.

A shaft support pin 18 is provided on the side plate 16 of the storage portion 14, and one end portion of the arm 20 is rotatably supported on the shaft support pin 18. Further, an arcuate guide hole 22 is formed in the side plate 16 of the storage portion 14 around the pivot pin 18, and a guide pin 24 attached to the arm 20 is passed through the guide hole 22. ing. Therefore, when the arm 20 rotates around the pivot pin 18, the guide pin 24 is guided along the guide hole 22.

[0034] The other end of the arm 20 is mounted on a mounting portion 28 provided on the upper rear side of the side plate 26 of the cabinet 12, and the cabinet 12 swings around the pivot pin 18 via the arm 20. It is possible to move.

On the other hand, shafts 32 and 34 are spanned between the pair of side plates 16 in the storage portion 14.

The shaft 34 is disposed on the front side of the side plate 16 and cannot rotate with respect to the side plate 16. Further, one end of an arm 36 is rotatably supported on the shaft 34, and the other end of the arm 36 is attached to a mounting portion 38 provided on the center side of the side plate 26 of the cabinet 12. The arm 36, together with the arm 20, enables the cabinet 12 to swing.

On the other hand, the shaft 32 is rotatably supported with respect to the side plate 16, and the driving force of the motor 40 that can rotate in the forward and reverse directions is transmitted to the shaft 32 via the gear train 42. ing

Yes

As shown in FIG. 3, a worm 44 is directly connected to the rotating shaft of the motor 40, and the driving force from the motor 40 is transmitted to the worm 44. A worm wheel 46A is engaged with the worm 44, and the worm wheel 46A is rotated by the rotation of the worm 44. This worm wheel 46A has a small gear 46B on its body. The small gear 46B is rotated by the rotation of the ohm wheel 46A. The small gear 46B is engaged with the large gear 48A, and the large gear 48A rotates as the small gear 46B rotates. The large gear 48A is provided with a small gear 48B, and the small gear 48B is rotated by the rotation of the large gear 48A. The small gear 48B is engaged with the large gear 50A, and the large gear 50A rotates as the small gear 48B rotates. The large gear 50A is provided with a force / tooth gear 50B on the body, and the force and the bevel gear 50B are rotated by the rotation of the large gear 50A. This force, the bevel gear 50B, meshes with the force fixed to the shaft 32, the bevel gear 52, and the rotation of the force and bevel gear 52 causes the shaft 32 to rotate.

Further, the motor 40 is provided with an encoder 41. The encoder 41 outputs a noise corresponding to the forward / reverse rotation of the motor 40 and the transfer rate.

[0039] Power transmission gears 54 are fixed to both ends of the shaft 32 (see Fig. 2). On the other hand, the side plate 16 of the storage portion 14 is provided with a disk-shaped arm swinging shaft plate 56 that rotates about the shaft support pin 18. The arm swinging shaft plate 56 has a guide pin 24 extending therethrough. An arm swinging gear 56A is formed on the outer peripheral surface of the arm swinging shaft plate 56, and the arm swinging gear 56A is driven by power. It is in mesh with transmission gear 54.

[0040] The arm swinging shaft plate 56 rotates around the shaft support pin 18 by the rotation of the power transmission gear 54, rotates the arm 20 while moving the guide pin 24 along the guide hole 22, and the cabinet. Move 12 up and down. Then, following the movement of the cabinet 12, the arm 36 rotates.

By the way, the cabinet 12 has a pair of support plates 60 hanging from the lower part of the front surface, and a bar-shaped gripping portion 62 is supported on the support plate 60.

[0042] As shown in FIGS. 4A and 4B, the gripping portion 62 is a cylindrical grip 6 made of resin.

4 and a flat metal plate 66 is provided inside the grip 64.

. The metal plate 66 is formed longer than the grip 64, and both ends of the metal plate 66 are fixed to the support plate 60.

[0043] Further, a gap is provided between the metal plate 66 and the grip 64. The grip 64 has a central portion in the longitudinal direction that is opposed to the front and back surfaces of the metal plate 66, respectively. A convex portion 64A is provided so as to face. Further, at both ends of the grip 64, leaf springs 68 are disposed in a gap provided between the metal plate 66, one end abuts against the front or back surface of the metal plate 66, and the other end. The portion abuts against the inner peripheral surface of the grip 64 and biases the grip 64 outward. Thereby, the positional relationship between the grip 64 and the metal plate 66 is maintained.

[0044] In addition, a metal part 70 (which may be any conductive member) is provided at the center of the grip 64, and a touch sensor 71 (see FIG. 5) is provided on the metal part 70. It is connected. The touch sensor 71 detects the capacitance of the metal part 70. The touch sensor 71 outputs a low level signal when the detected capacitance is less than a predetermined value, and outputs a high level signal when the detected capacitance exceeds a predetermined value. This predetermined value is set to an appropriate value capable of detecting that the user's hand has touched the metal part 70.

On the other hand, a strain sensor 72 is disposed at the center in the longitudinal direction of the metal plate 66 (see FIGS. 4A and 4B) so as to face the convex portion 64A. In the gripping part 62, the user grips the metal part 70 by hand and moves it up and down, so that the convex part 64 </ b> A contacts the metal plate 66 and the metal plate 66 is distorted.

[0046] The strain sensor 72 includes a strain gauge (not shown). The resistance value of a strain gauge changes depending on the direction and magnitude of the strain. The strain sensor 72 replaces the change in the resistance value of the strain gauge with the change in the voltage, amplifies it, and outputs it. When the strain sensor 72 is distorted according to the strain of the metal plate 66, the voltage level of the output signal changes. The voltage level of the signal output from the strain sensor 72 decreases according to the strain amount when the strain sensor 72 is distorted downward, and increases according to the strain amount when the strain sensor 72 is distorted upward. That is, by detecting the voltage level of the signal output from the strain sensor 72, the stress and direction acting on the grip 64 can be detected.

[0047] FIG. 5 shows a main configuration of an electric system of the electric hanging cabinet 10 according to the present embodiment.

[0048] As shown in the figure, the electric hanging cabinet 10 is capable of amplifying the voltage level of the signal output from the strain sensor 72 by a predetermined factor (1 X 106 times in this embodiment, but from 5000 times). is there) Based on the pulse output from the amplifier circuit 80 and the encoder 41, the rotation speed and rotation direction of the motor 40 are obtained, and the rotation speed and rotation direction and the voltage of the signal amplified by the amplification circuit 80 are obtained. A microcomputer (hereinafter referred to as “microcomputer”) 82 that outputs a speed control signal that controls the rotational speed of the motor 40 based on the level, and a drive circuit 84 that drives the motor 40 to rotate according to the speed control signal. I have.

[0049] Note that the signal output from the strain sensor 72 has several voltage levels, and the S / N ratio with noise generated in the wiring to which the signal is transmitted cannot be increased. For this reason, in the electric hanging cabinet 10 according to the present embodiment, the amplifier circuit 80 is provided as close to the strain sensor 72 as possible to shorten the wiring distance between the amplifier circuit 80 and the strain sensor 72 as much as possible. By performing amplification while suppressing the amount of noise generated as much as possible, the effect of noise is suppressed.

The microcomputer 82 has a CPU, ROM, RAM, and the like configured on one chip, and stores a drive control program, a potential difference target rotation speed conversion table, a reference voltage level, and the like, which will be described later, in the ROM in advance.

[0051] The drive circuit 84 changes the rotational speed of the motor 40 by changing the duty ratio of the drive signal output to the motor 40 in accordance with the speed control signal.

FIG. 6 schematically shows an example of the potential difference target rotation speed conversion table stored in the microcomputer 82 according to the present embodiment.

As shown in the figure, the potential difference target rotation speed conversion table stores the target rotation speed for each potential difference, and the value is set so that the target rotation speed increases as the absolute value of the potential difference increases. Is set. In the present embodiment, the rotation speed is a negative value when the rotation shaft of the motor 40 rotates in the direction of lowering the cabinet 12, and a positive value when the rotation speed of the cabinet 12 is increased. The direction of rotation is also shown.

FIG. 7 is a functional block diagram showing a functional configuration of the microcomputer 82 according to the present embodiment.

[0055] Microcomputer 82 detects target rotational speed acquisition unit 90 for acquiring the target rotational speed, and detects the noise input from encoder 41 for a certain period of time, and the rotational speed and rotational method of motor 40. The rotation speed detection unit 92 detects the rotation speed as a positive or negative value depending on the rotation direction, and the gain coefficient Kp used in PID control based on the rotation speed detected by the rotation speed detection unit 92 A gain coefficient deriving unit 94 for deriving and a PID control unit 96 for performing PID control using the derived gain coefficient Κρ and outputting a speed control signal are provided.

Note that the target rotational speed acquisition unit 90 is a voltage obtained by amplifying the signal output from the strain sensor 72 by the amplifier circuit 80 in a state in which no strain is generated in the strain gauge built in the strain sensor 72. The voltage level corresponding to the level is stored in advance as a reference voltage level. Then, when the signal input from the touch sensor 71 becomes a high level, the target rotation speed acquisition unit 90 obtains a potential difference from the voltage level of the signal input from the amplifier circuit 80 with reference to the reference voltage level, and determines the potential difference. Based on the potential difference target rotation speed conversion table, the target rotation speed is acquired.

[0057] The voltage of the signal output from the strain sensor 72 may change little by little due to changes in the external environment. For this reason, when the signal input from the touch sensor 71 is at a low level, the target rotation speed acquisition unit 90 corrects the stored reference voltage level based on the voltage level of the signal input from the amplifier circuit 80.

[0058] The gain coefficient deriving unit 94 stores in advance a predetermined conversion function with the rotation speed as an input value and the gain coefficient Kp as an output value. The gain coefficient Kp is calculated from the rotation speed using the conversion function. To derive.

By the way, in the PID control, as shown in FIG. 8, when the value of the gain coefficient Kp is increased, an overshoot occurs in which the rotational speed of the motor 40 exceeds the target rotational speed. If the value of the coefficient Kp is decreased, the time required for the motor 40 to reach the target rotational speed is lengthened and the speed response is lowered. Therefore, the optimum value of the gain coefficient K P is the largest value within a range where no overshoot occurs.

[0060] Therefore, the above conversion function indicates that the gain coefficient to be derived increases as the rotational speed of the motor 40 increases within a range in which overshoot does not occur in the rotational speed of the motor 40 when PID control is performed. It is predetermined to become. The gain coefficient deriving unit 94 according to the present embodiment derives a gain coefficient from the rotation speed using a conversion function. For example, a rotational speed gain coefficient conversion table that defines the relationship between the rotational speed and the gain coefficient so that the gain coefficient derived within the range where overshoot does not occur increases as the rotational speed increases. May be stored in advance, and the gain coefficient Kp may be derived from the rotational speed of the motor 40 based on the rotational speed gain coefficient conversion table.

[0061] Further, the PID control unit 96 obtains a deviation e of the rotation speed of the motor 40 with respect to the target rotation speed, an integral value obtained by time-integrating the deviation e, and a differential value obtained by time differentiation of the deviation e, respectively. The difference MV, the integral value, and the derivative value are added, and the value MV is obtained by multiplying the value obtained by the addition by the gain coefficient Kp, and the increase or decrease amount of the rotation speed of the motor 40 is determined according to the value MV. A speed control signal for instructing is output. The PID control unit 96 in FIG. 7 shows the flow of PID control in the Laplace transformed form, where Ti is the integration time, Td is the differentiation time, and s is the Laplace operator. Multiply the deviation e by l / (Ti 'S) to obtain the integral value, multiply the deviation e by Td' S to obtain the differential value, add the deviation e, the integral value and the differential value, The value MV is derived by multiplying the value obtained by the addition by the gain coefficient Kp.

By the way, the microcomputer 82 according to the present embodiment is assumed to realize the PID control described above by executing a drive control program.

[0063] Next, the operation of the electric hanging cabinet 10 according to the present embodiment will be described.

[0064] First, an overall operation flow when the user raises and lowers the cabinet 12 will be described with reference to FIGS. 9A to 9C and FIGS. 10A to 10C.

As shown in FIG. 9A, when the user lowers the cabinet 12 stored in the storage unit 14, the user grips the metal part 70 of the gripping part 62 with his hand and moves downward with respect to the gripping part 62. Caro X.

[0066] As a result, the convex portion 64A (see FIGS. 4A and 4B) provided inside the gripping portion 62 contacts the metal plate 66, and a downward strain is generated in the metal plate 66. Depending on the strain, the strain sensor 72 also generates downward strain (see Fig. 9B).

[0067] The microcomputer 82 obtains the target rotation speed based on the voltage level output from the strain sensor 72, and moves the rotation axis of the motor 40 to the cabinet 1 at the target rotation speed by PID control. By rotating 2 in the downward direction, assist the user in the downward movement of the cabinet 12 (see Figure 9C).

[0068] On the other hand, when the user raises the lowered cabinet 12, as shown in FIG. 1 OA, the user grips the metal part 70 of the grip part 62 with his / her hand and applies upward force to the grip part 62. Add

[0069] As a result, upward strain is generated in the metal plate 66 provided inside the grip portion 62, and upward strain is also generated in the strain sensor 72 (see FIG. 10B).

[0070] The microcomputer 82 obtains the target rotation speed based on the voltage level output from the strain sensor 72, and moves the rotation axis of the motor 40 to the cabinet 1 at the target rotation speed by PID control.

Rotating 2 in the direction of raising assists the user in raising the cabinet 12 (see Figure 10C).

[0071] As described above, the electric hanging cabinet 10 according to the present embodiment lifts the cabinet 12 by gripping the metal part 70 of the gripping part 62 by hand without the user performing an operation of separately specifying the assist operation. Since the assist is performed in accordance with the lowering operation, the operability is good.

[0072] In addition, the electric hanging cabinet 10 according to the present embodiment adjusts the speed at which the cabinet 12 is moved up and down by changing the strain amount of the strain sensor 72 by adjusting the force applied to the metal part 70 by the user. This improves usability.

Next, with reference to FIG. 11, the operation of the microcomputer 82 when executing the drive control program will be described in detail. The drive control program is executed when a power supply (not shown) of the electric hanging cabinet 10 is turned on, and ends when the power supply is turned off.

[0074] In step 102 of the figure, it is determined whether or not the signal input from the touch sensor 71 is at a high level. If the determination is affirmative, the process proceeds to step 106. If the determination is negative, The process proceeds to step 104 again.

In step 104, the stored reference voltage level is corrected to the voltage level of the signal input from the amplifier circuit 80, and the process proceeds to step 102 again. That is, the operations of Step 102 to Step 104 are repeated until the user's hand touches the metal part 70. As a result, for example, malfunction caused when strain occurs in the strain sensor 72 due to vibration or the like is prevented. In addition, since the reference voltage level is corrected in step 104, the voltage of the signal output from the strain sensor 72 due to a change in the external environment, etc. Even in the case of a change, it is possible to accurately detect the potential difference corresponding to the strain caused by gripping the metal part 70 of the gripping part 62 by hand in Step 106 described later.

In step 106, the potential difference between the voltage levels of the signals input from the amplifier circuit 80 is detected using the stored reference voltage level as a reference.

[0077] In the next step 108, based on the potential difference detected in step 106, a target rotational speed corresponding to the potential difference is acquired from the potential difference target rotational speed conversion table. 41, the rotational speed of the motor 40 is detected by detecting the input pulse. In the next step 112, the gain coefficient Kp is derived from the rotational speed of the motor 40 detected in the above step 110 using the above-described conversion function. To do.

[0078] Then, in the next step 114, the deviation e of the rotational speed of the motor 40 detected in step 110 with respect to the target rotational speed derived in step 108, an integrated value obtained by integrating the deviation e over time, and the deviation e as time. Each differentiated differential value is obtained, and the obtained deviation, integral value, and differential value are added, and the value obtained by the addition is multiplied by a gain coefficient Kp to calculate a direct MV.

[0079] In the next step 116, a speed control signal instructing an increase or decrease in the rotational speed is output according to the value MV calculated in step 114, and the process returns to step 102 described above to continue the process. And execute.

Here, FIG. 12A and FIG. 12B show changes in the rotational speed of motor 40 when the rotational speed of motor 40 is controlled by microcomputer 82 according to the present embodiment.

[0081] In the PID control by the drive control program according to the present embodiment, the gain coefficient derived by the conversion function becomes a large value as the rotational speed of the motor 40 increases, so as shown in FIG. The target rotational speed is fast! /, And the speed responsiveness of the rotational speed of the motor when the rotational speed is changed can be kept good.

[0082] Further, when the rotational speed of the motor 40 is low! /, The gain coefficient derived by the conversion function becomes a relatively small value, so that the target rotational speed vibrates as shown in FIG. 12B. Even in this case, the occurrence of hunting in the rotational speed of the motor can be suppressed. [0083] In addition, the electric hanging cabinet 10 according to the present embodiment increases the strain amount of the strain sensor 72 by applying a large force to the metal part 70 so that the user can raise and lower the cabinet 12 quickly. However, when the rotational speed of the motor 40 is low, the gain coefficient derived by the conversion function is a small value, and the cabinet 12 starts to move slowly.

As described above, according to this embodiment, the rotation speed of the motor is detected by the detection unit (here, the rotation speed detection unit 92), and is acquired by the acquisition unit (target rotation speed acquisition unit 90). The target rotational speed of the motor is acquired, and the derivation unit (in this case, the gain coefficient derivation unit 94) is configured to match the rotational speed of the motor with the target rotational speed according to the deviation of the rotational speed of the motor from the target rotational speed When performing feedback control, the detection unit detects a gain coefficient that amplifies the adjustment amount of the motor rotation speed within a range that does not cause an overshoot in which the motor rotation speed exceeds the target rotation speed. The higher the rotation speed is, the higher the value is derived, and the control unit (PID control unit 96) calculates the deviation of the rotation speed detected by the detection unit from the target rotation speed acquired by the acquisition unit. Based on the gain coefficient derived by the derivation unit! /, Feedback control is performed! /, So the target rotational speed vibrates during low-speed operation while suppressing a decrease in speed response. However, the occurrence of hunting in the rotational speed of the motor can be suppressed.

In the present embodiment, the force described in the case where the rotational speed of the motor 40 is feedback controlled by PID control. The present invention is not limited to this, for example, other feedback control such as PI control. The rotational speed of the motor 40 may be controlled by Also in this case, the same effects as in the present embodiment can be obtained.

Further, in the present embodiment, the force S described for the case where one gain coefficient Kp is derived from the rotational speed of the motor 40 by a conversion function, the present invention is not limited to this, for example, The proportional gain coefficient, integral gain coefficient, and differential gain coefficient are derived from the rotation speed by different conversion functions, and the value obtained by multiplying the deviation by the proportional gain coefficient and the integral value obtained by time-integrating the deviation are multiplied by the integral gain coefficient. A value obtained by multiplying the differential gain obtained by differentiating the value and the deviation with a differential gain coefficient may be obtained, and the rotational speed of the motor may be controlled based on the value obtained by adding the respective values. As a result, the motor Since the proportional gain coefficient, integral gain coefficient, and differential gain coefficient can be individually changed according to the rotational speed of 40, the response characteristics of the motor 40 can be controlled with great strength.

Further, in the present embodiment, the force described in the case of assisting the lifting / lowering operation of the cabinet 12 by the driving force of the motor 40. The present invention is not limited to this.

The present invention may be used for another electric assist device that assists the user's operation with respect to the assist target with the driving force of 40.

[0088] In addition, the configuration of the electric hanging cabinet 10 described in the present embodiment (see Figs. 1 to 4A and 4B), the electric system configuration of the electric hanging cabinet 10 (see Fig. 5), and the microcomputer 82. Functional configuration

(Refer to FIG. 7) is an example, and it goes without saying that it can be changed as appropriate without departing from the scope of the present invention! /.

In addition, the data structure of the potential difference target rotation speed conversion table (see FIG. 6) described in the present embodiment is also an example, and it goes without saying that it can be changed as appropriate without departing from the gist of the present invention. ! /

In addition, the processing flow of the drive control program (see FIGS. 10A to 10C) described in the present embodiment is also an example, and can be appropriately changed without departing from the gist of the present invention. Needless to say!

Industrial applicability

[0091] By suppressing the occurrence of hunting in the rotational speed of the motor even when the target rotational speed vibrates during low-speed operation while suppressing a decrease in the speed responsiveness of the motor, The present invention can be applied to a motor drive control device that performs feedback control of rotational speed, an electric assist device that includes the motor drive control device, and a responsive feedback control method.

Explanation of symbols

[0092] 40 motor

82 Microcomputer

90 Target rotation speed acquisition unit

92 Rotation speed detector

94 Gain factor deriving section PID controller

Claims

The scope of the claims

[1] a detection unit for detecting the rotation speed of the motor;

An acquisition unit for acquiring a target rotational speed of the motor;

When performing feedback control for controlling the motor rotational speed to match the target rotational speed according to a deviation of the motor rotational speed with respect to the target rotational speed, the rotational speed of the motor is set to the target rotational speed. The gain coefficient for amplifying the adjustment amount of the rotation speed of the motor within a range that does not cause excessive overshoot is derived so that the gain coefficient increases as the rotation speed detected by the detection unit increases. And outing,

A control unit that performs the feedback control based on a deviation of the rotation speed detected by the detection unit with respect to the target rotation speed acquired by the acquisition unit, and a gain coefficient derived by the derivation unit;

A motor drive control device.

[2] The control unit performs the feedback control based on the deviation, an integral value obtained by time-integrating the deviation, a differential value obtained by time-differentiating the deviation, and a gain coefficient derived by the derivation unit. , PID control

The motor drive control device according to claim 1.

[3] The control unit adds the deviation, the integral value, and the differential value, multiplies the value obtained by the addition by the gain coefficient, and based on the value obtained by the multiplication, Perform PID control

The motor drive control device according to claim 2.

[4] The motor drive control device according to any one of claims 1 to 3, and

An electric assist device comprising: a motor that is controlled by the motor drive control device and drives an assist target.

[5] The rotational speed of the motor is detected, the target rotational speed of the motor is acquired, and the rotational speed of the motor is matched with the target rotational speed according to a deviation of the rotational speed of the motor with respect to the target rotational speed. When the feedback control is performed, an overshoot is generated in which the rotational speed of the motor exceeds the target rotational speed. A gain coefficient that amplifies the adjustment amount of the rotation speed of the motor within a range that is not generated is derived so that the gain value increases as the detected rotation speed increases.

The feedback control is performed based on the detected deviation of the rotational speed with respect to the acquired target rotational speed, and the derived gain coefficient.

Responsive feedback control method.