JP2016137127A - Transfer support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer support device capable of suppressing output required for a driving system.SOLUTION: A transfer support device 1 includes a holding device 4 for holding a care-receiver, an arm 32a connected to the holding device 4 through a joint part 31a, an arm 32b connected to the arm 32a through the joint part 31b, a gravity detection part 54 for detecting a gravity position of the care-receiver, and a driving control part 55 for controlling angles of the joint part 31a and the joint part 31b. The driving control part 55 calculates a trajectory based on a moment arm with respect to the center of gravity of the care-receiver calculated from the gravity position detected by the gravity detection part 54, and executes control according to the trajectory.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a transfer support apparatus.

  In recent years, various transfer support devices have been developed for reducing the load when a care recipient is transferred between a bed and a wheelchair. For example, in Patent Document 1, the position of the center of gravity of a mass system including a plurality of mass points corresponding to the care recipient and the transfer support device is calculated, and the stability of the transfer support device is evaluated based on the calculated position of the center of gravity. A technique for controlling the operating state of the transfer support apparatus according to the stability evaluation result is disclosed.

JP 2010-158460 A

  When the transfer support device controls the operation regardless of the position of the center of gravity when performing the transfer support operation, an excessive load may be applied to the drive system depending on the position of the center of gravity. For this reason, the drive system is required to have output performance commensurate with the load, and there is a problem that the drive system is enlarged.

  The present invention has been made against the background of the above-described circumstances, and an object thereof is to provide a transfer support apparatus capable of suppressing an output required for a drive system.

  The transfer support apparatus according to the present invention includes a holder for holding a care recipient, a first arm connected to the holder via a first joint, and the first arm via a second joint. A second arm connected to one arm, a center-of-gravity detecting means for detecting the position of the center of gravity of the care recipient, and a control means for controlling the angles of the first joint part and the second joint part. The control means calculates a trajectory based on a moment arm with respect to the center of gravity of the care receiver calculated from the center of gravity position detected by the center of gravity detection means, and performs control according to the trajectory.

  According to such a transfer support device, since the operation can be controlled based on the trajectory corresponding to the center of gravity position of the care recipient, an operation suitable for the center of gravity position can be realized and the load can be suppressed. Therefore, the output required for the drive system of the transfer assist device can be suppressed, which can contribute to downsizing.

  ADVANTAGE OF THE INVENTION According to this invention, the transfer assistance apparatus which can suppress the output requested | required of a drive system can be provided.

It is a schematic diagram which shows the external appearance of the transfer assistance apparatus which concerns on embodiment. It is a block diagram which shows the schematic system configuration | structure of the transfer assistance apparatus which concerns on embodiment. It is a schematic diagram which shows the mode of the transfer operation | movement by the transfer assistance apparatus which concerns on embodiment. It is a block diagram which shows an example of a function structure of the control apparatus which concerns on embodiment. It is a figure showing the coordinate in the gravity center detection by the gravity center detection part which concerns on embodiment. It is a flowchart which shows an example of the gravity center detection process which concerns on embodiment. It is a flowchart which shows an example of the transfer assistance operation | movement in the transfer assistance apparatus which concerns on embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
<Embodiment 1>
FIG. 1 is a schematic diagram illustrating an appearance of a transfer support apparatus 1 according to the embodiment, and FIG. 2 is a block diagram illustrating a schematic system configuration of the transfer support apparatus 1. The transfer support device 1 includes a carriage 2, an arm group 3 supported by the carriage 2, a holder 4 provided at the tip of the arm group 3, an operation unit 5, and a control device 6.

  The carriage 2 is provided with wheels 21. The trolley 2 can perform arbitrary traveling such as forward / backward movement, left / right turn, acceleration / deceleration, and stop, for example, by rotationally driving the wheels 21. Specifically, the wheel 21 is rotationally driven by the operation of the cart drive mechanism 22. The cart drive mechanism 22 includes an actuator such as a motor (not shown) and drives the wheels 22 in accordance with a control signal from the control device 6.

  The arm group 3 includes a joint portion 31a, an arm 32a, a joint portion 31b, and an arm 32b. The arm 32a is also referred to as a first arm, and is connected to the holder 4 via the joint portion 31a. The joint portion 31a is also called a first joint portion, and rotates clockwise or counterclockwise in FIG. That is, the angle of the holder 4 with respect to the arm 32a is changed by the rotation of the joint portion 31a. Specifically, the joint portion 31a is rotated by the operation of the joint drive mechanism 33a. The joint drive mechanism 33 a includes an actuator such as a motor (not shown), for example, and operates according to a control signal from the control device 6.

  The arm 32b is also referred to as a second arm, and is connected to the arm 32a via the joint portion 31b. The end of the arm 32 b that is not connected to the arm 32 a is connected to the carriage 2, and the arm 32 b is fixed on the carriage 2. The joint portion 31b is also called a second joint portion, and rotates clockwise or counterclockwise in FIG. That is, the angle of the arm 32a with respect to the arm 32b is changed by the rotation of the joint portion 31b. Specifically, the joint portion 31b is rotated by the operation of the joint drive mechanism 33b. The joint drive mechanism 33 b includes an actuator such as a motor (not shown) and operates according to a control signal from the control device 6.

  The holder 4 holds a cared person. The transfer support device 1 drives the joint portion 31 a, the joint portion 31 b, or the wheel 21 to support the transfer operation of the cared person held by the holder 4. The operation unit 5 is an input device for operating the transfer assist device 1. The operation unit 5 includes, for example, an operation lever, detects the magnitude and direction of the operation force applied to the operation lever, and outputs an operation signal to the control device 6.

  The control device 6 includes, for example, a CPU (Central Processing Unit) 61 that performs control processing, arithmetic processing, and the like, a ROM (Read Only Memory) 62 that stores a control program executed by the CPU 61, an arithmetic program, processing data, and the like. The hardware configuration is centered on a microcomputer including a RAM (Random Access Memory) 63 and the like. The control device 6 outputs a control signal to each of the drive mechanisms described above according to the operation signal output from the operation unit 5, and controls each drive mechanism. Specifically, the control device 6 calculates the trajectories of the joint portions 31a and 31b according to the operation signal with respect to the motions of the joint portions 31a and 31b, and realizes the motion along the calculated trajectories. Control signals to be output to the joint drive mechanism 33a and the joint drive mechanism 33b.

  As illustrated in FIG. 3, the transfer support device 1 having the configuration described above moves the cared person 10 having the center of gravity G by driving the joint portion 31 a and the joint portion 31 b. In addition, the structure of said transfer assistance apparatus 1 is an example, and is not limited to this.

  FIG. 4 is a block diagram illustrating an example of a functional configuration of the control device 6. In the block diagram shown in FIG. 4, a part of the functional configuration of the control device 6 related to the drive control of the joint portion 31 a and the joint portion 31 b is shown, and other functional configurations are made easy to understand. The explanation is omitted. Note that each configuration shown in FIG. 4 is realized by the CPU 61 executing the control program or the arithmetic program, for example.

  The control device 6 includes a torque acquisition unit 51a, an angle acquisition unit 52a, a torque acquisition unit 51b, an angle acquisition unit 52b, a weight acquisition unit 53, a center of gravity detection unit 54, and a drive control unit 55. .

  The torque acquisition part 51a acquires the value of the torque generated in the joint drive mechanism 33a of the joint part 31a. The torque acquisition unit 51a may acquire the torque value by any known method. For example, when the actuator that generates torque in the joint drive mechanism 33a is a motor, the torque acquisition unit 51a is calculated by multiplying the measured value of the current flowing in the motor by the torque constant of the motor. What is necessary is just to acquire a torque value.

  The angle acquisition unit 52a acquires the angle of the joint part 31a. Specifically, the angle acquisition unit 52a acquires the angle of the holder 4 with reference to a predetermined reference coordinate axis. Here, the reference coordinate axis does not always coincide with the horizontal coordinate axis of the absolute coordinate system. For this reason, from the angle acquired by the angle acquisition unit 52a, the angle of the holder 4 when the horizontal coordinate axis of the absolute coordinate system is used as a reference is not immediately known. The angle acquisition unit 52a acquires an angle using, for example, a rotary encoder (not shown).

  The torque acquisition part 51b acquires the value of the torque generated in the joint drive mechanism 33b of the joint part 31b. The torque acquisition part 51b should just acquire the value of a torque by the well-known arbitrary methods similarly to the torque acquisition part 51a.

  The angle acquisition part 52b acquires the angle of the joint part 31b. Specifically, the angle acquisition unit 52b acquires the angle of the arm 32a with respect to the horizontal coordinate axis of the absolute coordinate system. The angle acquisition unit 52b acquires an angle using, for example, a rotary encoder (not shown).

  The weight acquisition unit 53 acquires the weight of the care recipient. For example, the weight acquisition unit 53 may acquire a weight input from a user or the like via an input device (not shown), or may acquire a weight by a weight sensor (not shown) provided in the holder 4 or the like. .

  The center of gravity detection unit 54 detects the position of the center of gravity of the care receiver. The center-of-gravity detection unit 54 detects the position of the center of gravity of the cared person by estimating the position of the center of gravity using the torque and angle at the joint part 31a, the torque and angle at the joint part 31b, and the weight of the cared person. The specific detection of the center of gravity position by the center of gravity detection unit 54 will be described later.

  The drive control unit 55 functions as a control unit and controls the angles of the joint portion 31a and the joint portion 31b. Specifically, the drive control unit 55 first calculates a trajectory based on the moment arm with respect to the center of gravity of the care receiver calculated from the position of the center of gravity detected by the center of gravity detection unit 54. The drive control unit 55 realizes, for example, the minimum moment arm under a predetermined constraint condition such as a ride comfort or a movable range limitation in the operation of the transfer support device 1 when the joint portion 31a and the joint portion 31b are operated. The trajectory to be calculated is calculated. Then, the drive control unit 55 outputs a control signal to the joint drive mechanism 33a and the joint drive mechanism 33b according to the calculated trajectory to control the angles of the joint unit 31a and the joint unit 31b.

Next, details of the center of gravity detection by the center of gravity detection unit 54 will be described with reference to FIG. In FIG. 5 and the following description, each variable is defined as follows.
T ₁ : A vector indicating the torque required to support the arm 32a in a state where the cared person is in the joint drive mechanism 33b of the joint portion 31b (that is, torque in a state balanced with the force in the gravity direction) T ₁ |: T ₁ size T ₂ : In the joint drive mechanism 33a of the joint portion 31a, the torque required for supporting the holder 4 in a state where the cared person is riding (ie, the force in the direction of gravity) T 2 | _| vector indicating the torque) of the balanced state: _{T 2} of size _{L OA:} vector towards the center of rotation a from the rotational center point O of the joint portion 31b joints 31a _{| L OA |:} L OA Size L _AG : Vector from the rotation center point A of the joint part 31a toward the center of gravity G of the cared person | L _AG |: L _AG magnitude L _OG : From the rotation center point O of the joint part 31b Center of gravity G Vector mg: cared person's weight vector | mg |: cared person's weight θ ₁ : angle of arm 32a with reference to horizontal coordinate axis θ ₂ : center of gravity G with reference to horizontal coordinate axis Angle θ _2offset : Angle Δθ ₂ formed by the above-mentioned reference coordinate axis and the horizontal coordinate axis: Angle G ′ of the center of gravity G with respect to the above-mentioned reference coordinate axis: Position of the center of gravity G on the horizontal coordinate axis The following relationship holds for variables.

In the above equation, | mg | is acquired by the weight obtaining unit 53, theta ₁ is acquired by the angle acquisition unit 52b. | L _OA | is a known value because it corresponds to the length of the arm 32a. Here, the angle [Delta] [theta] ₂ of the center of gravity G relative to the reference coordinate axes, when the difference between the angle of the holder 4 relative to the reference coordinate axes that are acquired by the angle acquisition unit 52a and theta _d, theta _d is obtained For example, Δθ ₂ can be obtained based on the angle acquired by the angle acquisition unit 52a. If θ _2offset is obtained, θ ₂ can be obtained from equation (5). If | T ₁ | is acquired by the torque acquisition unit 51b, | L _AG | can be obtained from Equation (2), and therefore the coordinate position of the center of gravity G can be detected.

Specifically, the centroid detection unit 54 detects the coordinate position of the centroid G in the following flow. FIG. 6 is a flowchart for explaining the flow of centroid detection in the centroid detection unit 54. In the following flowcharts, first obtains the theta _2Offset in step 100 and step 101, and obtains the theta _d in step 104 from step 102. This will be specifically described below.

  In step 100 (S100), the joint portion 31a is changed in a state where the cared person is not on the holder 4. In addition, the angle of the holder 4 shall be horizontal at one time in the case of this fluctuation | variation.

In step 101 (S101), the torque value acquired by the torque acquisition unit 51a is monitored, and the angle of the holder 4 at the time when the torque value becomes maximum at the time of the _change is acquired as _θ2offset . In addition, the angle of the holder 4 acquired here is an angle based on the reference coordinate axis acquired by the angle acquisition unit 52a. When the torque value becomes maximum, it is assumed that the holder 4 is in a horizontal state. For this reason, the angle acquired by the angle acquisition unit 52a at this time is equal to θ _2offset .

  In step 102 (S102), the joint part 31a is changed in a state where the cared person gets on the holder 4. In addition, the angle of the holder 4 shall be horizontal at one time in the case of this fluctuation | variation.

In step 103 (S103), the torque value acquired by the torque acquisition unit 51a is monitored, and the angle θ ′ of the holder 4 when the torque value becomes maximum at the time of the change is acquired. Θ ′ is the angle of the holder 4 with reference to the reference coordinate axis acquired by the angle acquisition unit 52a. When the torque value becomes maximum, it is assumed that _LAG is in a horizontal state. That is, at this time, θ ₂ = 0.

In step 104 (S104), first, Δθ ₂ is calculated. Since θ ₂ = 0 and θ _{2 offset} is acquired in step 101, Δθ ₂ is calculated from equation (5). Then, since this [Delta] [theta] ₂ and the angle obtained in step 103 theta ', calculates the theta _d by θ'-Δθ _2.

  In step 105 (S105), the angle θ ″ of the holder 4 is acquired in a state where the cared person gets on the holder 4. The angle θ ″ of the holder 4 acquired here is obtained by the angle acquisition unit 52a. This is the angle obtained with reference to the reference coordinate axis. In step 105, the angle of the holder 4 is fixed at an arbitrary angle.

In step 106 (S106), the angle theta ₂ of the center of gravity G at this time is calculated using Equation (5). In Equation (5), θ _2offset is known, and Δθ ₂ is obtained by θ ″ −θ _d .

  In step 107 (S107), the torque for driving the joint portion 31b is increased in a state where the angle of the holder 4 is fixed.

At step 108 (S108), a torque value when the angle theta ₁ of the arm 32a is started to increase | is obtained as | _{T 1.} The torque value | T ₁ | is acquired by the torque acquisition unit 51b. When the angle theta ₁ of the arm 32a starts to increase, the torque in the joint portion 31b is assumed the state commensurate with the gravity force. Therefore, it can be acquired as | T ₁ |.

In step 109 (S109), | L _AG | is calculated from equation (2). Specifically, | L _AG | is the obtained | T ₁ |, | mg | obtained by the weight obtaining unit 53, the known | L _OA |, and θ obtained by the angle obtaining unit 52b. ₁ and θ ₂ obtained based on the angle acquired by the angle acquisition unit 52a. When | L _AG | is obtained, the coordinate position of the center of gravity G is calculated from the positional relationship shown in FIG.

  As described above, the coordinate position of the gravity center G is detected by the gravity center detection unit 54. Next, a transfer support operation in the transfer support apparatus 1 will be described. FIG. 7 is a flowchart illustrating an example of the operation of the transfer support apparatus 1.

  In step 10 (S10), the center-of-gravity detector 54 detects the position of the center of gravity G of the care recipient. In addition, what showed the flow of the specific process of step 10 is the flowchart shown by the above-mentioned FIG.

  In step 11 (S11), the drive control unit 55 calculates a trajectory based on the moment arm with respect to the center of gravity of the cared person calculated from the position of the center of gravity detected in step 10. The moment arm with respect to the center of gravity of the cared person corresponds to the length from the rotation center point O to the position G ′ on the coordinate axis in the horizontal direction of the center of gravity G.

  In step 12 (S12), the drive control unit 55 controls the angles of the joint portion 31a and the joint portion 31b according to the trajectory calculated in step 11.

  Thus, since the transfer assistance apparatus 1 can control operation | movement based on the track | orbit according to the cared person's gravity center position, operation | movement suitable for a gravity center position can be implement | achieved and load can be suppressed. That is, since the transfer operation is realized on the trajectory where the moment arm is minimized, the output required for the drive system of the transfer support device 1 can be suppressed. Therefore, it is not necessary for the transfer support apparatus 1 to have redundant output characteristics, and the mounted actuator, battery, and the like can be reduced in size.

<Embodiment 2>
Next, a second embodiment will be described. In the first embodiment, θ _d , which is a deviation amount between the angle of the holder 4 acquired by the angle acquisition unit 52a and the angle of the center of gravity G, is calculated. In the present embodiment, the center of gravity position is calculated by approximating the angle of the center of gravity G with the angle of the holder 4 acquired by the angle acquisition unit 52a. That is, in the present embodiment, the angle of the center of gravity G is regarded as the angle of the holder 4.

For this reason, in the center-of-gravity detection unit 54 according to the second embodiment, the above-described calculation process of θ _d is omitted. Specifically, the processing from step 102 to step 104 shown in FIG. 6 is omitted. In addition, in order to perform the above approximation, in the present embodiment, Δθ ₂ is acquired by the angle acquisition unit 52 a in step 106.

According to the transfer support apparatus 1 according to the second embodiment, there is a possibility that an error may occur between the actual angle of the center of gravity G and the angle of the center of gravity G used for detecting the position of the center of gravity. Can be detected. Moreover, the output requested | required of the drive system of the transfer assistance apparatus 1 can be suppressed similarly to Embodiment 1. FIG.
In the present embodiment, although the angle of the center of gravity G are considered as the angle of the holder 4, it may be a fixed value which is determined the theta _d advance.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Transfer assistance apparatus 2 Carriage 4 Holding tool 6 Control apparatus 31a, 31b Joint part 32a, 32b Arm 33a, 33b Joint drive mechanism 51a, 51b Torque acquisition part 52a, 52b Angle acquisition part 53 Weight acquisition part 54 Center of gravity detection part 55 Drive Control unit

Claims (1)

A holding tool for holding the cared person;
A first arm connected to the holder via a first joint,
A second arm connected to the first arm via a second joint;
Centroid detection means for detecting the centroid position of the care recipient;
Control means for controlling the angles of the first joint part and the second joint part,
The transfer support device, wherein the control means calculates a trajectory based on a moment arm with respect to the center of gravity of the care receiver calculated from the center of gravity position detected by the center of gravity detection means, and performs control according to the trajectory.

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