JP2007175170A - Load varying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constantly retain the dimension of a load applied to an operating handle even if the load generated by a loading device is varied and adjust the dimension of the constantly applied load. <P>SOLUTION: When the operating handle 3 is operated in the inverse direction to a prescribed direction against a load generated in the prescribed direction by the loading device 5 with a torque command value S set by a torque set value setting part 7, a control circuit 8 controls a motor 9, according to the dimension of the torque detected by a torque sensor 6 and the dimension of the torque command value S, to generate a torque of the dimension equivalent to a difference between the torque detected by the torque sensor 6 and the torque command value S in the same direction or the inverse direction to the direction of the torque detected by the torque sensor 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a load variable device that varies a load applied to an operation handle for a load applied to the operation handle by a load device.

  In a training device used for human strength training or a rehabilitation device used for rehabilitation, the size of the load applied to the operation handle is generally set by increasing or decreasing the number of weights. . In this case, the load can be set only stepwise for each weight per weight, and a fine load cannot be set.

  Therefore, in recent training devices and rehabilitation devices, a weight is not used as a means for applying a load to the operation handle, but a load generated by the load device is provided to the operation handle and applied to the operation handle. A device using a load variable device that varies the load is considered.

  As this type of load variable device, for example, a device described in Patent Document 1 is configured such that an input shaft rotated by a load device and an output shaft that can rotate together with an operation handle are connected via a coupling device. When the operation handle is operated, the torque generated in the operation handle and the rotation angle of the operation handle are detected by the physical quantity detector, and the energization amount of the coupling device is increased or decreased based on the detection result. Yes.

At this time, if the energization amount of the coupling device is increased, the degree of coupling between the input shaft and the output shaft increases, so that the load generated by the load device is operated via the input shaft and the output shaft. It becomes easy to be transmitted to the handle, and the load applied to the operation handle is increased. Conversely, if the amount of current flowing through the coupling device is reduced, the degree of coupling between the input shaft and the output shaft weakens, so the load generated by the load device can be operated via the input shaft and output shaft. It becomes difficult to be transmitted to the handle, and the load applied to the operation handle is reduced. As a result, when the user operates the operation handle, the load applied to the operation handle is continuously changed according to the torque generated in the operation handle and the rotation angle of the operation handle.
Japanese Patent Laid-Open No. 5-180245

  In the load variable device having the above-described configuration, the load applied to the operation handle depends on the energization amount of the coupling device (degree of coupling between the input shaft and the output shaft). However, the characteristics of this coupling device may change due to, for example, heat or wear. In such a case, even if the energization amount is kept constant, the load generated by the load device fluctuates. It was difficult to keep the load applied to the operation handle constant.

  In addition, for example, when using a training device or a rehabilitation device using this type of load variable device, there is a need for the user to perform training or rehabilitation with a desired load. Since the load applied to the operation handle is configured to change only based on the torque generated on the operation handle or the rotation angle of the operation handle, it cannot be adjusted to the size desired by the user. In some cases, the user's needs could not be met.

  The present invention has been made in view of the circumstances described above, and the purpose thereof is to keep the load applied to the operation handle constant even when the load generated by the load device fluctuates. An object of the present invention is to provide a load variable device capable of adjusting the magnitude of the constant load.

  The load variable device according to claim 1 is a torque sensor that detects a magnitude and direction of a torque that acts on a shaft that connects the operation handle and the load device, and a torque command value setting unit that can set a torque command value. The operation handle moves in the predetermined direction against a load in a predetermined direction generated by the load device in a state where the torque command value is set by the motor for generating torque on the shaft and the torque command value setting means. Is compared with the torque command value set by the torque command value setting means and the direction of the torque detected by the torque sensor is compared with the torque command value set by the torque command value setting means. And the magnitude of the torque detected by the torque sensor is determined from the torque command value set by the torque command value setting means. When the torque is larger, the magnitude corresponds to the difference between the magnitude of the torque detected by the torque sensor and the torque command value set by the torque command value setting means, and the direction of the torque detected by the torque sensor And motor control means for controlling the motor so as to generate torque in the opposite direction on the shaft.

According to the load variable device of the first aspect, if the magnitude of the torque detected by the torque sensor is larger than the torque command value, the magnitude of the load applied to the operation handle is determined from the load generated by the load device. Even if the load generated by the load device fluctuates by performing feedback control in this way, the load applied to the operation handle is reduced by the amount of torque generated by the rotation of the motor. Can be kept constant at a load corresponding to the magnitude of the torque command value.
Further, since the load applied to the operation handle can be set as the torque command value, the load applied to the operation handle can be adjusted.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description, the load variable device 1 is applied to, for example, a training device 2 used for human strength training as shown in FIG. 2, and the user sits on the chair 2 a of the training device 2 and operates the operation handle 3. Assuming that the load applied to the operation handle 3 in the directions of arrows A1 and A2 in FIG. 2 is varied when the operation handle 3 is operated in the directions of arrows A1 and A2 in FIG. This will be specifically described.

  As shown in FIG. 1, the base 3a of the operation handle 3 described above is connected to one end side (left end side in FIG. 1) of the shaft 4, and rotates the operation handle 3 in the directions of arrows A1 and A2 in FIG. In conjunction with the rotation of the operation handle 3, the shaft 4 is rotated in the directions of arrows B1 and B2 in FIG. On the other hand, the other end side of the shaft 4 (the right end side in FIG. 1) is connected to a load device 5 constituted by, for example, a hysteresis brake, so that the shaft 4 can rotate in the directions of arrows B1 and B2 in FIG. On the other hand, a load in the directions of arrows B2 and B1 in FIG. 1 is generated.

The load variable device 1 includes a torque sensor 6, a torque command value setting unit 7 (corresponding to torque command value setting means), a control circuit 8 (corresponding to motor control means), and a motor 9.
The torque sensor 6 is interposed in a portion of the shaft 4 that connects the operation handle 3 and the load device 5. For example, the operation handle 3 moves in the direction of arrow A1 (A2) in FIG. 2 (predetermined) against the load in the direction of arrow B2 (B1) in FIG. The torque is detected by detecting the magnitude and direction of the torque acting on the shaft 4 (corresponding to the direction of the load generated by the load device 5). The sensor signal T is output to the torque input terminal 10 of the control circuit 8.

The torque command value setting unit 7 can set the magnitude of the load desired by the user as the torque command value S by operating an operation dial (not shown). Then, the set torque command value S is output to the torque command value input terminal 11 of the control circuit 8.
The control circuit 8 includes a signal processing circuit 12, a zero adjustment circuit 13, an absolute value circuit 14, a polarity determination circuit 15, a subtracter 16, a PWM current control circuit 17, and a driver circuit 18.

  The signal processing circuit 12 amplifies the torque sensor signal T from the torque sensor 6 to a voltage level corresponding to the magnitude of the torque and rectifies the torque sensor signal T to a polarity corresponding to the direction of the torque, thereby generating a torque composed of a DC voltage signal. Convert to signal Vt. The zero point adjustment circuit 13 performs zero point adjustment of the torque signal Vt output from the signal processing circuit 12 and outputs it to the absolute value circuit 14 and the polarity determination circuit 15.

  The absolute value circuit 14 rectifies the voltage level of the torque signal Vt input from the zero point adjustment circuit 13 (the magnitude of the torque detected by the torque sensor 6) and subtracts it as a voltage signal Vt1 indicating the magnitude of the torque. 16 is applied to one input terminal (−). The torque command value S from the torque command value setting unit 7 is given to the other input terminal (+) of the subtracter 16. Then, the subtracter 16 obtains a voltage deviation ΔV (ΔV = Vt1−S) between the level of the voltage signal Vt1 and the level of the torque command value S and outputs it to the PWM current control circuit 17.

  The PWM current control circuit 17 controls the level of the drive signal D supplied to the motor 9 in proportion to the magnitude of the voltage deviation ΔV from the subtracter 16. More specifically, when the voltage deviation ΔV is large (when the difference between the magnitude of the torque detected by the torque sensor 6 (voltage signal Vt1) and the magnitude of the load desired by the user (torque command value S) is large. Is controlled so that the level of the drive signal D supplied to the motor 9 is increased. On the other hand, when the voltage deviation ΔV is small, the level of the drive signal D supplied to the motor 9 is controlled to be small. That is, the rotational force (output torque) of the motor 9 increases as the difference between the load desired by the user and the torque detected by the torque sensor 6 increases.

  The polarity discriminating circuit 15 discriminates the polarity (torque direction detected by the torque sensor 6) of the torque signal Vt input from the zero adjustment circuit 13, and uses the discrimination result as a polarity signal Vt2 indicating the torque direction. This is applied to the circuit 18.

  The driver circuit 18 controls the polarity (direction) of the drive signal D supplied to the motor 9 based on the polarity of the voltage deviation ΔV and the polarity of the polarity signal Vt2. More specifically, when the polarity of the voltage deviation ΔV is positive (the magnitude of the torque detected by the torque sensor 6 (voltage signal Vt1) is larger than the magnitude of the load desired by the user (torque command value S). ) Controls the polarity of the drive signal D supplied to the motor 9 in the opposite direction to the polarity of the polarity signal Vt2 (the direction of the torque detected by the torque sensor 6). On the other hand, when the polarity of the voltage deviation ΔV is negative (when the magnitude of the torque detected by the torque sensor 6 (voltage signal Vt1) is smaller than the magnitude of the load desired by the user (torque command value S)), The polarity of the drive signal D supplied to the motor 9 is controlled in the same direction as the polarity of the polarity signal Vt2.

  A motor 9 is connected to the output terminal 19 of the control circuit 8, and when the motor 9 is given a drive signal D from the control circuit 8, the rotating shaft 20 rotates in the directions of arrows C1 and C2 in FIG. It has become. The rotating shaft 20 is connected to a worm wheel gear 21 disposed on the shaft 4, and when the rotating shaft 20 is rotated in the directions of arrows C 1 and C 2 in FIG. Is rotated in the directions of arrows B1 and B2 in FIG.

  At this time, the motor 9 rotates in the direction corresponding to the polarity of the drive signal D with the rotational force corresponding to the magnitude of the level of the drive signal D, whereby the magnitude of the torque detected by the torque sensor 6 and the torque command. Torque is generated in the shaft 4 in a direction corresponding to the difference from the value S and in the same direction as or opposite to the direction of the torque detected by the torque sensor 6.

Next, the operation of the above configuration will be described.
When the user operates the operation handle 3 in the directions of arrows A1 and A2 in FIG. 2 in a state where a desired load magnitude (torque command value S) is set via the torque command value setting unit 7, FIG. , (B), the size corresponding to the load in the direction of arrows B1, B2 in FIG. 1 generated by the load device 5 (the size of the arrow a in FIG. 3 (a), the size in FIG. 3 (b) The torque in the direction of the load generated by the load device 5 (the downward direction in FIGS. 3A and 3B) acts on the shaft 4. Then, the torque sensor 6 detects the magnitude and direction of the torque.

  At this time, when the magnitude of the torque detected by the torque sensor 6 (torque corresponding to the load generated by the load device 5) is larger than the torque command value S (see FIG. 3A), the drive signal D Is controlled to a magnitude corresponding to the difference between the magnitude of the torque detected by the torque sensor 6 (voltage signal Vt1) and the magnitude of the load desired by the user (torque command value S). Is controlled in a direction opposite to the direction of the torque detected by the torque sensor 6.

  When the motor 9 is rotated based on this drive signal D, the difference between the magnitude of the torque detected by the torque sensor 6 (the magnitude of the load generated by the load device 5) and the magnitude of the torque command value S. 3 (the size of the arrow b in FIG. 3A) and the direction opposite to the direction of the torque detected by the torque sensor 6 (the direction of the load generated by the load device 5) (FIG. 3A). Then, upward torque is generated in the shaft 4. Therefore, the magnitude of the load applied to the operation handle 3 is reduced by the magnitude of the torque generated by the rotation of the motor 9 from the magnitude of the load generated by the load device 5 (FIG. 3 ( a) The size of the middle arrow c).

  On the other hand, when the magnitude of the torque detected by the torque sensor 6 (torque corresponding to the load generated by the load device 5) is smaller than the torque command value S (see FIG. 3B), the drive signal D The level is controlled to a magnitude corresponding to the difference between the magnitude of the torque detected by the torque sensor 6 (voltage signal Vt1) and the magnitude of the load desired by the user (torque command value S). The polarity (direction) is controlled in the same direction as the direction of the torque detected by the torque sensor 6.

  When the motor 9 is rotated based on this drive signal D, the difference between the magnitude of the torque detected by the torque sensor 6 (the magnitude of the load generated by the load device 5) and the magnitude of the torque command value S. 3 (the size of the arrow h in FIG. 3B) and the same direction as the direction of the torque detected by the torque sensor 6 (the direction of the load generated by the load device 5) (FIG. 3B) Then, a downward torque is generated in the shaft 4. Therefore, the magnitude of the load applied to the operation handle 3 is increased by the magnitude of the torque generated by the rotation of the motor 9 to the magnitude of the load generated by the load device 5 (FIG. 3 ( b) The size of the middle arrow i).

  Incidentally, the load generated by the load device 5 may fluctuate. In this case, the torque detected by the torque sensor 6 (for example, see the arrow d in FIG. 3A and the arrow j in FIG. 3B). Although the magnitude also varies, when the magnitude of the torque detected by the torque sensor 6 is greater than the torque command value S by performing the series of feedback control described above, the load applied to the operation handle 3 Is reduced by the amount of torque generated by the rotation of the motor 9 (the size of the arrow e in FIG. 3A) from the size of the load generated by the load device 5. It is kept constant at (the size of the arrow f in FIG. 3A). On the other hand, when the magnitude of the torque detected by the torque sensor 6 is smaller than the torque command value S, the magnitude of the load applied to the operation handle 3 is set to the magnitude of the load generated by the load device 5. Is kept constant at a magnitude (size of arrow l in FIG. 3 (b)) increased by the magnitude of torque generated by rotation (size of arrow k in FIG. 3 (b)). It is.

  As described above, according to the present embodiment, the magnitude of the load applied to the operation handle 3 according to the magnitude of the torque detected by the torque sensor 6 and the torque command value S depends on the load device 5. Since the motor 9 is configured to be reduced or increased by the magnitude of the torque generated by the rotation of the motor 9, the load device 5 is generated by performing the feedback control in this way. Even if the load to be changed fluctuates, the load applied to the operation handle 3 can be kept constant at the load corresponding to the torque command value S (the load desired by the user). The user can operate the operation handle 3 without feeling uncomfortable.

In particular, if the magnitude of the torque detected by the torque sensor 6 (the load generated by the load device 5) is smaller than the torque command value S, the operation handle 3 is loaded with a load greater than the load generated by the load device 5. In addition, the load can be kept constant.
In addition, since the load applied to the operation handle 3 can be set as the torque command value S, the load applied to the operation handle 3 can be adjusted.
Further, it is not always necessary to use the high-performance load device 5, and an inexpensive or small-sized load device can be used.

In addition, this invention is not limited only to above-described embodiment, It can expand or deform | transform as follows.
In the above-described embodiment, the training apparatus 2 configured to operate the operation handle 3 is applied to the present invention, but the shaft rotates in conjunction with the movement of the portion operated by the user. For example, the present invention can be applied to a training device or a rehabilitation device configured to rotate a pedal.

The functional block diagram which shows one Embodiment of this invention and shows a load variable apparatus and a periphery structure Perspective view schematically showing the appearance of the training device The figure for demonstrating the effect | action of this invention

Explanation of symbols

  In the drawings, 1 is a load variable device, 3 is an operation handle, 4 is a shaft, 5 is a load device, 6 is a torque sensor, 7 is a torque command value setting unit (torque command value setting means), and 8 is a control circuit (motor control). Means), 9 indicates a motor.

Claims (2)

A torque sensor for detecting the magnitude and direction of the torque acting on the shaft connecting the operation handle and the load device;
A torque command value setting means capable of setting a torque command value;
A motor for generating torque on the shaft;
When the operation handle is operated in a direction opposite to the predetermined direction against a load in a predetermined direction generated by the load device in a state where the torque command value is set by the torque command value setting means, The torque detected by the torque sensor is compared with the torque command value set by the torque command value setting means, the direction of the torque detected by the torque sensor is determined, and the torque detected by the torque sensor Is larger than the torque command value set by the torque command value setting means, the magnitude of the torque detected by the torque sensor and the torque command value set by the torque command value setting means. Torque in a direction corresponding to the difference and in the direction opposite to the direction of the torque detected by the torque sensor Load changing device being characterized in that a motor control means for controlling said motor so as to generate a.   When the magnitude of the torque detected by the torque sensor is smaller than the torque command value set by the torque command value setting means, the motor control means determines the magnitude of the torque detected by the torque sensor and the The motor is controlled so as to cause the shaft to generate a torque having a magnitude corresponding to the difference from the torque command value set by the torque command value setting means and in the same direction as the torque detected by the torque sensor. The load variable device according to claim 1, wherein:

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