JP2008141923A - Motor drive control device, power assist device, and responsive feedback control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive control device that suppresses the occurrence of hunting in a rotation speed of a motor while suppressing deterioration in speed responsiveness even when a target rotation speed varies during low-speed operation, a power assist device, and a responsive feedback control method. <P>SOLUTION: A rotation speed detection part 92 detects a rotation speed of a motor 40. A target rotation speed acquisition part 90 acquires a target rotation speed of the motor 40. A gain-factor derivation part 94 derives a gain factor for amplifying an adjustment amount of the rotation speed of the motor 40 as a value, in which the faster the detected rotation speed is the larger the value is, within a range preventing the occurrence of overshoot that causes the rotation speed of the motor 40 to exceed the target rotation speed. A PID control part 96 executes feedback control to the rotation speed of the motor 40 on the basis of the derived gain factor and a deviation of the detected rotation speed with respect to the acquired target rotation speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  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 control device that performs feedback control of a rotation speed of a motor (more specifically, a rotation speed of a rotor of a motor), The present invention relates to an electric assist device including the motor drive control device and a responsive feedback control method.

  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, it was inconvenient for the hanging cabinet to take in and out heavy items and large items.

Therefore, as a technique for facilitating the taking in and out of articles with respect to the hanging cupboard, Patent Document 1 is provided with an inner box that moves 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 cabinet that is configured is described. In this electric lifting / lowering hanging rack, when the article is taken in and out, the switch provided in the operation unit is operated to lower the inner box, thereby making it easy to put the article into and out of the hanging rack.
JP 2005-21298 A

  By the way, when the raising / lowering speed of the inner box is lowered, the electric lifting / lowering cabinet described in Patent Document 1 lowers the inner box to a position where an article can be taken in and out, or the inner box is located at a position where the inner box is stored in the outer box. It took a long time to raise 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 raising / lowering distance by which the inner box moves up and down becomes longer before the user instructs the operation unit to stop the raising / lowering operation of the inner box.

  For this reason, when applying the electric lifting / lowering cabinet described in Patent Document 1, the actual situation is that the lifting / lowering speed must be reduced.

  Therefore, for example, a grip portion such as a grip bar is provided in the inner box, and the direction and magnitude of the strain generated in the grip bar when the user applies a force to raise and lower the inner box with respect to the grip bar are detected. Rotational speed according to the force applied to the grip bar by obtaining the target rotational speed of the motor according to the detection result and performing feedback control to control the rotational speed of the motor to match the target rotational speed An electric hanging cabinet provided with an electric assist device that assists the user in raising and lowering the inner box by rotating the motor is conceivable.

  Incidentally, PID control is known as a kind of such feedback control. This PID control is feedback control using both P control (proportional control), I control (integral control), and D control (differential control). For example, the motor rotational speed deviation (speed difference) with respect to the target rotational speed, The integral value obtained by time-integrating the deviation and the differential value obtained by time-differentiating the deviation are obtained, and the obtained deviation, the integral value, and the differential value are added, and the value obtained by the addition is multiplied by a predetermined gain coefficient. Then, 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, and as an example, as shown in FIG. When the speed is changed, the arrival time until the rotational speed of the motor reaches the target rotational speed is short, and the speed responsiveness 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.

  For example, the electric hanging cabinet provided with the above-described electric assist device that assists the user in raising and lowering the inner box controls the rotational speed of the motor by PID control, and the gain coefficient is set to a relatively large value. To do. In this case, if the user attempts to gently lift the inner box by adjusting the force applied to the grip bar, the motor rotation speed adjustment amount corresponding to the strain amount of the grip bar is large. The raising / lowering speed at which the inner box moves up / down with the rotation of the user box becomes faster than the raising / lowering speed of the user's hand raising / lowering the grip bar, and the hand may be left behind.

  Thus, when the hand is left behind, the strain amount 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 amount of distortion of the grip bar increases and the target rotation speed increases, and the lifting speed of the inner box becomes the lifting speed of the user's hand. As a result, the speed is again increased and the hand is left again with respect to the grip bar. As a result, hunting occurs in the rotational speed of the motor along with the vibration of the target rotational speed.

  In the electric assist device that assists the user's operation on the assist target with the driving force of the motor, when 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 operation cannot be assisted smoothly.

  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 rotational speed of the motor corresponding to the deviation is small, and as shown in FIG. 14B as an example. Even when 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 arrival time until the rotational speed of the motor reaches the target rotational speed becomes long, and the speed responsiveness is increased. There was a problem that was low.

  The present invention has been made to solve the above-described problems, and hunting occurs in 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 this.

  In order to achieve the above object, the invention according to claim 1 is a detection means for detecting a rotation speed of a motor, an acquisition means for acquiring a target rotation speed of the motor, and a rotation speed of the motor with respect to the target rotation speed. When performing feedback control for controlling the motor rotational speed to match the target rotational speed according to the deviation of the motor, within a range where the motor rotational speed does not cause an overshoot exceeding the target rotational speed. A derivation means for deriving a gain coefficient for amplifying an adjustment amount of the rotation speed of the motor so that the gain coefficient increases as the rotation speed detected by the detection means increases; and the target acquired by the acquisition means Based on the deviation of the rotational speed detected by the detection means with respect to the rotational speed, and the gain coefficient derived by the derivation means And and control means for performing serial feedback control.

  According to the first aspect of the present invention, when performing the feedback control for controlling the motor rotation speed so as to coincide with the target rotation speed according to the deviation of the motor rotation speed with respect to the target rotation speed, the derivation means performs the motor control. The gain coefficient that amplifies the adjustment amount of the motor rotational speed is within a range that does not cause an overshoot in which the rotational speed of the motor exceeds the target rotational speed, and the rotational speed detected by the detecting means that detects the rotational speed of the motor is fast It is derived so as to be a large value.

  In the present invention, based on the deviation of the rotational speed detected by the detection means with respect to the target rotational speed acquired by the acquisition means for acquiring the target rotational speed of the motor by the control means, and the gain coefficient derived by the derivation means. Feedback control is performed.

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

  Thus, according to the first aspect of the present invention, 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 targeted according to the deviation of the rotational speed of the motor with respect to the target rotational speed. When performing feedback control to match the rotation speed, 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 rotation speed of the motor exceeds the target rotation speed, Derived so that the faster the detected rotational speed, the larger the value, and feedback control is performed based on the deviation of the detected rotational speed with respect to the acquired target rotational speed and the derived gain coefficient. Suppresses the occurrence of hunting in the rotational speed of the motor even when the target rotational speed vibrates during low-speed operation Rukoto can.

  The control means according to the present invention is derived by the deviation, the integral value obtained by integrating the deviation over time, the differential value obtained by time-differentiating the deviation, and the derivation means as the feedback control. PID control may be performed based on the gain coefficient.

  According to a third aspect of the present invention, the control means adds the deviation, the integral value, and the differential value, multiplies the value obtained by the addition by the gain coefficient, and performs the multiplication. The PID control may be performed based on the value obtained by the above.

  On the other hand, in order to achieve the above object, an electric assist device according to claim 4 is controlled by the motor drive control device according to any one of claims 1 to 3 and the motor drive control device, and is an assist target. A motor for driving the object.

  Therefore, according to the electric assist device of the fourth aspect, since it operates in the same manner as the first aspect of the invention, similarly to the first aspect of the invention, while suppressing a decrease in speed responsiveness, Even when the target rotational speed vibrates, it is possible to suppress the occurrence of hunting in the rotational speed of the motor. Thereby, a user's operation | movement with respect to an assist target object can be assisted smoothly.

  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, obtains the target rotational speed of the motor, and rotates the rotational speed of 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 deviation of the motor, within a range where the motor rotational speed does not cause an overshoot exceeding the target rotational speed. A gain coefficient for amplifying the adjustment amount of the rotation speed of the motor 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. The feedback control is performed based on the gain coefficient.

  Therefore, according to the responsiveness feedback control method of the fifth aspect, since it operates in the same manner as the first aspect of the invention, it is possible to reduce the speed responsiveness while suppressing the decrease in the speed responsiveness, as in the first aspect of the invention. Even when the target rotational speed vibrates during operation, it is possible to suppress the occurrence of hunting in the rotational speed of the motor.

  As described above, according to the present invention, the rotation speed of the motor is detected, the target rotation speed of the motor is acquired, and the rotation speed of the motor is set to the target rotation according to the deviation of the rotation speed of the motor with respect to the target rotation speed. When performing feedback control to match the speed, the gain coefficient that amplifies the adjustment amount of the motor rotation speed is detected within the range that does not cause overshoot that the motor rotation speed exceeds the target rotation speed The higher the rotational speed is, the higher the speed is derived, and the feedback control is performed based on the detected rotational speed deviation with respect to the acquired target rotational speed and the derived gain coefficient. Suppresses the occurrence of hunting in the rotational speed of the motor even when the target rotational speed vibrates during low-speed operation. Can have an excellent effect that.

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

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

  As an example, the electric hanging cupboard 10 is used for ceiling installation used in a system kitchen. The electric hanging cabinet 10 includes a box-shaped cabinet 12 in which tableware and the like can be stored. 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 of an arm 20 is rotatably supported on the shaft support pin 18. 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 inserted into the guide hole 22. . For this reason, when the arm 20 rotates around the pivot pin 18, the guide pin 24 is guided along the guide hole 22.

  The other end of the arm 20 is mounted on a mounting portion 28 provided on the rear upper portion of the side plate 26 of the cabinet 12, and the cabinet 12 can swing around the pivot pin 18 via the arm 20. It is said that.

  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 portion of an arm 36 is rotatably supported on the shaft 34, and the other end portion 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. 36 allows the cabinet 12 to swing together with the arm 20.

  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 capable of rotating in the forward and reverse directions is transmitted to the shaft 32 via the gear train 42.

  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. The worm wheel 46A is integrally provided with a small gear 46B, and the small gear 46B is rotated by the rotation of the worm wheel 46A. The small gear 46B meshes with the large gear 48A, and the large gear 48A rotates as the small gear 46B rotates. The large gear 48A is integrally 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 meshes with the large gear 50A, and the large gear 50A rotates as the small gear 48B rotates. The large gear 50A is integrally provided with a bevel gear 50B, and the bevel gear 50B is rotated by the rotation of the large gear 50A. The bevel gear 50 </ b> B meshes with a bevel gear 52 fixed to the shaft 32, and the shaft 32 is rotated by the rotation of the bevel gear 52.

  The motor 40 is provided with an encoder 41. The encoder 41 outputs pulses according to the forward / reverse rotation of the motor 40 and the transfer rate.

  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 pivot pin 18. The arm swing shaft plate 56 is penetrated by the guide pin 24, and an arm swing gear 56A is formed on the outer peripheral surface of the arm swing shaft plate 56. The arm swing gear 56A transmits power. It meshes with the gear 54.

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

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

  As shown in FIGS. 4A and 4B, the gripping portion 62 includes a cylindrical grip 64 formed of resin, and a flat metal plate 66 is provided inside the grip 64. ing. The metal plate 66 is formed longer than the grip 64, and both end portions of the metal plate 66 are fixed to the support plate 60.

  In addition, a gap is provided between the metal plate 66 and the grip 64, and a convex portion 64 </ b> A is provided at the center in the longitudinal direction of the grip 64 so as to face the front surface and the back surface of the metal plate 66, respectively. Is provided. Further, at both ends of the grip 64, a leaf spring 68 is 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 grips. The grip 64 is abutted against the inner peripheral surface of 64 and biased toward the outside. Thereby, the positional relationship between the grip 64 and the metal plate 66 is maintained.

  Further, 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 connected to the metal part 70. ing. 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 the 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 FIG. 4) 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.

  The strain sensor 72 includes a strain gauge (not shown). The resistance value of the strain gauge changes depending on the direction and magnitude of the strain. The strain sensor 72 replaces a change in the resistance value of the strain gauge with a change in 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.

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

As shown in the figure, the electric hanging cabinet 10 increases the voltage level of the signal output from the strain sensor 72 by a predetermined value (1 × 10 ⁶ times in this embodiment, but can be amplified from 5000 times). The rotation speed and rotation direction of the motor 40 are obtained based on the amplification circuit 80 to be amplified and the pulse output from the encoder 41, and the motor is based on the rotation speed and rotation direction and the voltage level of the signal amplified by the amplification circuit 80. A microcomputer (hereinafter referred to as “microcomputer”) 82 for outputting a speed control signal for controlling the rotational speed of the motor 40 and a drive circuit 84 for rotating the motor 40 in accordance with the speed control signal are provided.

  The signal output from the strain sensor 72 has a voltage level of about several μV, and the S / N ratio with the 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, and the wiring distance between the amplifier circuit 80 and the strain sensor 72 is made as short as possible to generate the wiring. By performing amplification with the amount of noise to be suppressed as much as possible, the influence of noise is suppressed.

  The microcomputer 82 includes a CPU, a ROM, a RAM, and the like on one chip, and previously stores a drive control program, a potential difference target rotation speed conversion table, a reference voltage level, and the like in the ROM.

  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, this potential difference target rotation speed conversion table stores a target rotation speed for each potential difference, and a value is set so that the target rotation speed increases as the absolute value of the potential difference increases. Yes. In this embodiment, the rotation speed is set to a negative value when the rotation axis of the motor 40 rotates in the direction of lowering the cabinet 12, and as a positive value when rotated in the direction of raising the cabinet 12. The direction is also shown.

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

  The microcomputer 82 detects the rotation speed and the rotation direction of the motor 40 by detecting a pulse input from the encoder 41 during a certain period of time and a target rotation speed acquisition unit 90 that acquires the target rotation speed, and increases according to the rotation direction. Alternatively, a rotation speed detection unit 92 that detects a rotation speed as a negative value, and a gain coefficient deriving unit 94 that derives a gain coefficient Kp used in PID control based on the rotation speed detected by the rotation speed detection unit 92 are derived. A PID control unit 96 that performs PID control using the gain coefficient Kp and outputs a speed control signal.

  The target rotational speed acquisition unit 90 corresponds to a voltage level obtained by amplifying the signal output from the strain sensor 72 by the amplifier circuit 80 in a state where no strain is generated in the strain gauge built in the strain sensor 72. The voltage 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.

  Further, the voltage of the signal output from the strain sensor 72 may change little by little due to changes in the external environment. Therefore, 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.

  The gain coefficient deriving unit 94 stores in advance a predetermined conversion function having the rotation speed as an input value and the gain coefficient Kp as an output value, and derives the gain coefficient Kp from the rotation speed using the conversion function.

  By the way, in the PID control, as shown in FIG. 8, when the value of the gain coefficient Kp is increased, an overshoot in which the rotation speed of the motor 40 exceeds the target rotation speed occurs, and the value of the gain coefficient Kp is changed. If it is made smaller, the arrival time until the rotational speed of the motor 40 reaches the target rotational speed is lengthened, and the speed responsiveness is lowered. Accordingly, the optimum value of the gain coefficient Kp is the largest value within a range where no overshoot occurs.

  Therefore, the above conversion function is such that the gain coefficient to be derived becomes larger as the rotational speed of the motor 40 increases within a range where no overshoot occurs in the rotational speed of the motor 40 when PID control is performed. It is predetermined. The gain coefficient deriving unit 94 according to the present embodiment derives the gain coefficient from the rotation speed using a conversion function. For example, the gain coefficient deriving section 94 derives the gain coefficient within a range in which overshoot does not occur as the rotation speed increases. The rotational speed gain coefficient conversion table that defines the relationship between the rotational speed and the gain coefficient is stored in advance so that the gain coefficient to be obtained becomes a large value, and the rotation of the motor 40 is performed based on the rotational speed gain coefficient conversion table. The gain coefficient Kp may be derived from the speed.

  Further, the PID control unit 96 obtains a deviation e of the rotational speed of the motor 40 with respect to the target rotational speed, an integral value obtained by time-integrating the deviation e, and a differential value obtained by time-differentiating the deviation e, respectively. And a differential value, a value MV obtained by multiplying the value obtained by the addition by a gain coefficient Kp is obtained, and a speed control for instructing an increase or decrease in the rotational speed of the motor 40 according to the value MV Output a signal. 7 shows the flow of PID control in a Laplace-transformed form, where Ti is an integration time, Td is a differentiation time, and s is a Laplace operator. An integral value is obtained by multiplying the deviation e by 1 / (Ti · S), a differential value is obtained by multiplying the deviation e by Td · S, and the deviation e, the integral value and the differential value are added, 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 realizes the above-described PID control by executing a drive control program.

  Next, the effect | action of the electric hanging cupboard 10 which concerns on this Embodiment is demonstrated.

  First, with reference to FIG.9 and FIG.10, the flow of the whole operation | movement when a user raises / lowers the cabinet 12 is demonstrated.

  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 / her hand and moves downward with respect to the gripping part 62. Apply power.

  As a result, the convex portion 64 </ b> A (see FIG. 4) provided inside the gripping portion 62 comes into contact with the metal plate 66, and a downward strain is generated in the metal plate 66, and a strain sensor according to the strain of the metal plate 66. 72 also has a downward strain (see FIG. 9B).

  The microcomputer 82 acquires the target rotation speed based on the voltage level output from the strain sensor 72, and rotates the rotation axis of the motor 40 in the direction in which the cabinet 12 is lowered at the target rotation speed by PID control. Assists the lowering operation of the cabinet 12 (see FIG. 9C).

  On the other hand, as shown in FIG. 10A, when the user raises the lowered cabinet 12, the user grips the metal part 70 of the grip part 62 with his hand and applies an upward force to the grip part 62. .

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

  The microcomputer 82 acquires the target rotation speed based on the voltage level output from the strain sensor 72, and rotates the rotation axis of the motor 40 in the direction in which the cabinet 12 is raised at the target rotation speed by PID control. Assisting the ascending operation of the cabinet 12 (see FIG. 10C).

  As described above, the electric hanging cabinet 10 according to the present embodiment raises and lowers the cabinet 12 by grasping the metal part 70 of the grasping part 62 by hand without performing an operation of separately specifying an assist operation by the user. Since the assist is performed according to the operation, the operability is good.

  Moreover, since the electric hanging cupboard 10 which concerns on this Embodiment can adjust the speed which raises / lowers the cabinet 12 by adjusting to the force which a user applies with respect to the metal part 70, and changing the distortion amount of the distortion sensor 72, Usability is improved.

  Next, the operation of the microcomputer 82 when executing the drive control program will be described in detail with reference to FIG. 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.

  In step 102 in 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, whereas if the determination is negative, the step is performed again. 104.

  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 comes into contact with the metal part 70. Thereby, for example, a malfunction is prevented when strain occurs in the strain sensor 72 due to vibration or the like. In addition, since the reference voltage level is corrected in step 104, even if the voltage of the signal output from the strain sensor 72 changes due to a change in the external environment or the like, It is possible to accurately detect a potential difference corresponding to a strain caused by holding 62 metal parts 70 by hand.

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

  In the next step 108, the target rotational speed corresponding to the potential difference is acquired from the potential difference target rotational speed conversion table based on the potential difference detected in step 106, and in the next step 110, it is input from the encoder 41 for a fixed time. The rotation speed of the motor 40 is detected by detecting the pulse, and in the next step 112, the gain coefficient Kp is derived from the rotation speed of the motor 40 detected in the step 110 using the above-described conversion function.

  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 integral value obtained by integrating the deviation e over time, and a derivative obtained by time differentiation of the deviation e. Each value is obtained, and the obtained deviation, integral value and derivative value are added, and the value MV is calculated by multiplying the value obtained by the addition by the gain coefficient Kp.

  In the next step 116, a speed control signal for instructing the amount of increase or decrease in the rotational speed is output in accordance with the value MV calculated in step 114, and the process returns to the above-described step 102 to continue the process.

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

  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 rotation speed of the motor 40 increases, and as shown in FIG. The speed responsiveness of the rotation speed of the motor when the target rotation speed is changed to a high rotation speed can be kept good.

  Further, when the rotational speed of the motor 40 is low, the gain coefficient derived by the conversion function becomes a relatively small value, and therefore, as shown in FIG. 11B, the target rotational speed vibrates. In addition, the occurrence of hunting in the rotational speed of the motor can be suppressed.

  Moreover, even if the electric hanging cupboard 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 in order for the user to raise and lower the cabinet 12 quickly, When the rotational speed of the motor 40 is low, since the gain coefficient derived by the conversion function is a small value, the cabinet 12 starts to move slowly, so that it is easy to handle even for elderly people.

  As described above, according to the present embodiment, the rotation speed of the motor is detected by the detection means (here, the rotation speed detection section 92), and the target rotation of the motor is detected by the acquisition means (target rotation speed acquisition section 90). Feedback control is performed to acquire the speed and control the derivation means (here, the gain coefficient derivation unit 94) to make the motor rotation speed coincide with the target rotation speed in accordance with the deviation of the motor rotation speed from the target rotation speed. When performing, the gain coefficient that amplifies the adjustment amount of the motor rotation speed is larger as the rotation speed detected by the detection means is faster, so long as the motor rotation speed does not cause an overshoot that exceeds the target rotation speed. Is derived by the control means (PID control unit 96) and detected by the detection means for the target rotational speed acquired by the acquisition means. Since feedback control is performed based on the rotational speed deviation and the gain coefficient derived by the deriving means, the motor is controlled even when the target rotational speed vibrates during low speed operation while suppressing a decrease in speed response. Hunting can be suppressed from occurring at the rotation speed.

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

  In the present embodiment, the case where one gain coefficient Kp is derived from the rotation speed of the motor 40 by a conversion function has been described. However, the present invention is not limited to this, and for example, the proportional gain is calculated from the rotation speed. A coefficient, an integral gain coefficient, and a differential gain coefficient are derived by different conversion functions, the value obtained by multiplying the deviation by a proportional gain coefficient, the value obtained by integrating the deviation over time, the value obtained by multiplying the integral gain coefficient, and the deviation over time. A value obtained by multiplying the differentiated differential value by a differential gain coefficient may be obtained, and the rotational speed of the motor may be controlled based on a value obtained by adding the respective values. Thereby, since the proportional gain coefficient, the integral gain coefficient, and the differential gain coefficient can be individually changed according to the rotation speed of the motor 40, the response characteristics of the motor 40 can be finely controlled.

  Further, in the present embodiment, the case where the lifting / lowering operation of the cabinet 12 is assisted by the driving force of the motor 40 has been described. However, the present invention is not limited to this, and the driving force of the motor 40 is used to assist the assist target object. You may use for the other electric assist apparatus which assists a user's operation | movement.

  In addition, the configuration of the electric hanging cabinet 10 described in the present embodiment (see FIGS. 1 to 4), the configuration of the electric system of the electric hanging cabinet 10 (see FIG. 5), and the functional configuration of the microcomputer 82 (see FIG. 7) is an example, and it is needless to say that it can be appropriately changed without departing from the gist of the present invention.

  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 the data structure can be changed as appropriate without departing from the gist of the present invention.

  The processing flow of the drive control program (see FIG. 10) described in this 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.

It is a perspective view which shows the structure of the electric hanging cupboard in the state in which the cabinet which concerns on embodiment was accommodated. It is a perspective view which shows the structure of the electric hanging cupboard in the state where the cabinet which concerns on embodiment fell. It is an enlarged view which shows the detailed structure of the gear train which concerns on embodiment. (A) is a cross-sectional view of the gripping portion, and (B) is a vertical cross-sectional view of the gripping portion. It is a block diagram which shows the principal part structure of the electric system of the electric hanging cupboard which concerns on embodiment. It is a schematic diagram which shows an example of the data structure of the electric potential difference target rotational speed conversion table which concerns on embodiment. It is a block diagram which shows the function structure of the microcomputer which concerns on embodiment. It is a graph which shows the relationship of the change of the rotational speed of the motor for every gain coefficient. It is a figure which shows the operation | movement at the time of descent | falling the cabinet of the electric hanging cupboard which concerns on embodiment. It is a figure which shows the operation | movement at the time of accommodating the cabinet of the electric hanging cupboard which concerns on embodiment. It is a flowchart which shows the flow of a process of the drive control program which concerns on embodiment. It is a graph which shows an example of the change of the rotational speed of the motor at the time of controlling the rotational speed of the motor by PID control concerning an embodiment. It is a graph which shows an example of the change of the rotational speed of the motor at the time of controlling the rotational speed of the motor by the conventional PID control. It is a graph which shows an example of the change of the rotational speed of the motor at the time of controlling the rotational speed of the motor by the conventional PID control.

Explanation of symbols

40 motor 82 microcomputer 90 target rotation speed acquisition unit 92 rotation speed detection unit 94 gain coefficient deriving unit 96 PID control unit

Claims (5)

Detecting means for detecting the rotational speed of the motor;
Obtaining means for obtaining a target rotational speed of the motor;
When performing feedback control for controlling the motor rotational speed to match the target rotational speed in accordance with 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. Deriving means for deriving a gain coefficient for amplifying the adjustment amount of the rotational speed of the motor within a range in which excessive overshoot does not occur so that the gain coefficient increases as the rotational speed detected by the detecting means increases. ,
Control means for performing the feedback control based on a deviation of the rotation speed detected by the detection means with respect to the target rotation speed acquired by the acquisition means, and a gain coefficient derived by the derivation means;
A motor drive control device. The control means performs PID control as 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 means. The motor drive control device according to 1. The control means adds the deviation, the integral value and the derivative value, multiplies the value obtained by the addition by the gain coefficient, and performs the PID control based on the value obtained by the multiplication. The motor drive control device according to claim 2. A motor drive control device according to any one of claims 1 to 3,
A motor that is controlled by the motor drive control device and drives an assist target;
Electric assist device with While detecting the rotational speed of the motor, obtaining the target rotational speed of the motor,
When performing feedback control for controlling the motor rotational speed to match the target rotational speed in accordance with 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. Within a range that does not cause excessive overshoot, a gain coefficient that amplifies the adjustment amount of the rotation speed of the motor is derived so as to increase 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.

Images