JP6475282B2 - Electric bed - Google Patents

Description

  The present invention relates to a technology of an electric bed that can control the undulation operation, and more particularly, to an electric bed for treatment or nursing care.

  Conventionally, a technique is known in which an actuator is driven via a motor to operate a link mechanism to raise and lower a bed (for example, see Patent Document 1). Such an electric bed is mainly used for medical treatment in a hospital or nursing care in a home.

  In order to realize this undulation operation in the electric bed, link mechanisms of various structures have been put into practical use, and some use a hydraulic actuator and others use a motor type actuator. In many cases, the link mechanism is operated by driving an actuator via the actuator. In particular, an electric bed for treatment or nursing can generally adjust three operations, ie, a back-raising angle, a knee-lifting height, and a bed height, in an almost stepless manner.

  However, such electric beds are roughly classified into two types: a first type that does not perform feedback control and a second type that performs feedback control.

  In the first type, while the operator confirms the display value displayed on the operation switch, the actuator is driven via the motor to operate the link mechanism, and the operator operates the position at the position where the desired value is obtained. It is to stop. Many of the first type electric beds are relatively inexpensive.

  However, for example, in the case where the subject of treatment or care using an electric bed is restricted with respect to its back angle, knee height, and bed height under the guidance of a doctor, the first type electric bed The back raising angle, the knee raising height, and the bed height are arbitrarily adjusted according to the judgment of the operator, so that there is a possibility that the operation is erroneously performed.

  Therefore, in the second type, setting values that restrict the back-raising angle, knee-lifting height, and bed height are input in advance using the operation switch, and the actuator is driven via a motor to link the mechanism. When the motor is operated, the amount of rotation of the motor is detected by an encoder or a potentiometer to perform feedback control.

  In this second type of electric bed, for example, when a subject of treatment or care using an electric bed is restricted with regard to its back angle, knee height, and bed height under the guidance of a doctor, Corresponding set values are set in advance using operation switches. And when an operator drives an actuator via a motor with a switch for operation and operates a link mechanism, it operates without exceeding the set value by feedback control. For this reason, the second type electric bed is realized as a safe and secure electric bed for the operator or for the target of treatment or care.

  In particular, in the second type of electric bed, fine movements such as a back-up angle and a knee-lifting height are variably controlled at the same time so as to reduce the physical burden on the subject to be landed. Interlocking control such as speed control such as down can be realized, and such control cannot be realized with the first type electric bed.

  FIG. 10 shows an example of a conventional typical second type electric bed 10. FIG. 11 shows a schematic configuration of the switch 11 of the conventional typical second type electric bed 10.

  Referring to FIG. 10, in a conventional typical second type electric bed 10, a controller 12, a motor 13, an actuator 14, and a link mechanism 16 are disposed below a bed frame 17 that supports a human body. . In particular, a total of three sets of the motor 13, the actuator 14, and the link mechanism 16 are provided so that the step-up angle, the knee-lifting height, and the bed height can be adjusted almost steplessly.

  A harness for driving each motor 13 is connected to the controller 12. Each actuator 14 is connected to an output shaft of each motor 13, and a cylinder of each actuator 14 is connected to each link mechanism 16. The output shaft of each motor 13 is provided with a rotation amount detection sensor 15 for detecting the rotation amount of an encoder, a potentiometer, etc., and the output signal of this rotation amount detection sensor 15 is sent to each signal cable (see FIG. (Not shown) and connected to the controller 12.

  The operation switch 11 is connected to the controller 12, and the operator uses the switch 11 to adjust the step-up angle, the knee-lifting height, and the bed height of the landing portion 18 almost steplessly. Can be done.

  The switch 11 of the second type electric bed 10 schematically shows only main functions in FIG. 11, but is provided with a set value display unit 111 and an operation / setting button unit 112. The set value display unit 111 displays the current set values for the back-raising angle, the knee-lifting height, and the bed height on the setting display units 111a, 111b, and 111c.

  The operation / setting button unit 112 is provided with a setting button 112d and an operation button 112e. When the setting button 112d is pressed, the setting mode is set. When the operation button 112e is pressed, the operation mode is set. The LED display part 112g lights up.

Press the setting button 112d and setting mode, the up and down buttons 112a, by operating the 112b, 112 c, back lifting angle, knee lifting height, and can be set to each the desired set point for the bed height The set values are displayed on the set value display unit 111, respectively.

Press the operation button 112e and the operation mode, the up and down buttons 112a, by operating the 112b, 112 c, back lifting angle within not to exceed the setting value, knee lifting height, and the variable operation of the bed height It is possible to operate without exceeding the set value by feedback control.

  In the example shown in FIG. 11, for example, the operation buttons for operating the back raising angle and the knee raising height by variably interlocking control are omitted, but when this operation button is pressed, the operation is slowed up. Alternatively, the variable operation is automatically performed up to the position of the set value together with speed control such as slowdown.

  FIG. 12 shows a schematic configuration of a functional unit that realizes an operation during the entire operation of the conventional typical second type electric bed 10 as described above. Referring to FIG. 12, first, an operation signal in the operation mode is output from the switch 11 to the controller 12.

  When the controller 12 receives an operation signal based on a predetermined set value relating to the back raising angle, the knee raising height, and the bed height, the controller 12 supplies a drive signal to the motor 13 and realizes a corresponding operation. A rotation amount signal indicating the rotation amount of the corresponding motor 13 is input and monitored from each rotation amount detection sensor 15 such as a potentiometer or a potentiometer, and a state corresponding to the predetermined set value is obtained based on the rotation amount. Feedback control is performed.

  The cylinders of the actuators 14 that adjust the back-raising angle, the knee-lifting height, and the bed height respectively expand and contract according to the rotation of the motor 13 and are electrically driven via the link mechanisms 16 according to the expansion and contraction. The variable operation of the landing portion 18 in the bed 10 is performed.

  In addition, although it is not an electric bed, the technique using a 1 axis | shaft acceleration sensor for the detection of the said back raising angle is disclosed (for example, refer patent document 2).

JP 2014-12054 A Japanese Patent Laying-Open No. 2015-136579

  As described above, the first type of electric bed that does not perform feedback control may be erroneously operated.

  On the other hand, the second type of electric bed that performs feedback control is realized as a safe and secure electric bed for the operator or for the target of treatment or care.

  However, the conventional second type electric bed is configured to perform feedback control using a rotation amount detection sensor that detects the rotation amount of an encoder, a potentiometer, or the like. The meter has the property that a cumulative error occurs. For this reason, encoders and potentiometers used for electric beds for treatment and nursing care are required to have extremely high accuracy and low error specifications, and are expensive. As a result, the electric bed is also expensive.

  In addition, the second type of electric bed in the past does not detect the actual position of the landing part, but the amount of rotation of the motor is determined by the encoder or potentiometer based on the amount of rotation of the landing part and the height of knee rise. Because the feedback control is performed by indirectly estimating the bed height, the landing part may be deformed when there is an error between the actual landing part position and the motor rotation amount, or due to secular change. If this happens, it will be necessary to reset or recalibrate.

Accordingly, a second type of electric bed performing feedback control, to allow lower Ren reduction, besides techniques to achieve high accuracy of the feedback control is desired.

  More preferably, with respect to the first type electric bed, it is possible to add the second type electric bed only by adding and changing components that are cheaper and easier to retrofit than newly purchasing the second type electric bed. The technique to change into an electric bed is desired.

  More preferably, a technique of changing the second type electric bed to the second type electric bed with high accuracy only by adding and changing components having a configuration easy to be retrofitted is desired.

An object of the present invention, in view of the above problems, is to provide an electric bed which allows controlling the relief operation capable of realizing a lower Ren a Note and accurate feedback control.

The electric bed of the present invention is an electric bed that can control the undulation operation by feedback control, and a switch that generates an operation signal based on a predetermined set value for executing the predetermined undulation operation on the landing portion; A controller that receives the operation signal in a wired or wireless manner and that controls a drive mechanism that performs the predetermined undulation operation on the landing portion; and a state sensor that is installed at a movable portion related to the movement of the landing portion A feedback control unit that feedback-controls execution of the predetermined undulation operation by the drive mechanism based on a sensor signal from the state sensor, and is provided in either the switch or the controller, and the feedback The control unit monitors the sensor signal from the state sensor so as to be in a state corresponding to the predetermined set value. There line the feedback control, the predetermined relief operation consists of two or more relief operation, the state sensor, one provided on a common movable part in said two or more relief operation, said predetermined relief operation It is characterized in that it is installed in a number smaller than the number of types .

  In the electric bed according to the present invention, the drive mechanism includes a motor-driven actuator.

  In the electric bed according to the present invention, the state sensor may be a sensor capable of detecting an inclination of the movable part with respect to an absolute coordinate axis.

  In the electric bed of the present invention, the state sensor may be a sensor capable of detecting the inclination of the movable part corresponding to each axis with respect to two or more absolute coordinate axes.

  In the electric bed of the present invention, the state sensor includes a gyro sensor, an angle sensor, an acceleration sensor, or an impact sensor.

According to the present invention, it is possible to configure an electric bed which allows realizing a lower Ren a Note and accurate feedback control.

It is a figure which shows schematic structure of the electric bed of 1st Embodiment by this invention. It is a block diagram which shows schematic structure of the function part which implement | achieves the operation | movement at the time of operation of the whole electric bed of 1st Embodiment by this invention. It is a block diagram which shows schematic structure of the feedback (FB) control part in the electric bed of 1st Embodiment by this invention. It is a flowchart which shows the operation | movement at the time of operation of the whole electric bed of 1st Embodiment by this invention. It is a figure which shows schematic structure of the electric bed of 2nd Embodiment by this invention. It is a block diagram which shows schematic structure of the function part which implement | achieves the operation | movement at the time of operation of the whole electric bed of 2nd Embodiment by this invention. It is a flowchart which shows the operation | movement at the time of operation of the whole electric bed of 2nd Embodiment by this invention. It is a principle figure at the time of performing angle detection by two axes (two dimensions) about the state sensor used for feedback control concerning the present invention. In the feedback control according to the present invention, when the feedback control is performed only with the x axis (one dimension) at the actual angle θ = 0 to 70 °, when the feedback control is performed with only the y axis (one dimension), and x, y It is a figure which shows roughly distribution of each angle error in the case of performing feedback control by an axis | shaft (two dimensions). It is a figure which shows the example of the conventional typical 2nd type electric bed. It is a figure which shows schematic structure of the switch of the conventional typical 2nd type electric bed. It is a block diagram which shows schematic structure of the function part which implement | achieves the operation | movement at the time of the whole operation of the conventional typical 2nd type electric bed.

  Hereinafter, with reference to drawings, electric bed 1 of each embodiment by the present invention is explained.

[First Embodiment]
(Device configuration)
FIG. 1 is a diagram showing a schematic configuration of an electric bed 1 according to a first embodiment of the present invention. FIG. 2 is a block diagram showing a schematic configuration of a functional unit that realizes an operation during the entire operation of the electric bed 1 according to the first embodiment of the present invention. 1 and 2, the same reference numerals are assigned to the same components as those of the conventional electric bed 10 shown in FIGS. 10 to 12.

  Referring to FIGS. 1 and 2, the electric bed 1 according to the first embodiment of the present invention has an amount of rotation such as an encoder or a potentiometer as compared with the conventional electric bed 10 shown in FIGS. Based on the sensor signal from the state sensors 20a, 20b, and 20c, the point that the rotation amount detection sensor to detect is not provided, the point that the three state sensors 20a, 20b, and 20c are provided, and the inside of the controller 12. Although different in that a feedback (FB) control unit 30 is provided, the other components are the same.

  More specifically, in the electric bed 1 according to the first embodiment shown in FIG. 1, a controller 12, a motor 13, an actuator 14, and a link mechanism 16 are disposed below a bed frame 17 that supports a human body. In particular, a total of three sets of the motor 13, the actuator 14, and the link mechanism 16 are provided so that the step-up angle, the knee-lifting height, and the bed height can be adjusted almost steplessly.

  A harness for driving each motor 13 is connected to the controller 12. Each actuator 14 is connected to an output shaft of each motor 13, and a cylinder of each actuator 14 is connected to each link mechanism 16.

  The operation switch 11 is connected to the controller 12, and the operator uses the switch 11 to adjust the step-up angle, the knee-lifting height, and the bed height of the landing portion 18 almost steplessly. Can be done. The configuration of the switch 11 can be the same as that shown in FIG. In the example shown in FIG. 11, for example, the operation buttons for operating the back raising angle and the knee raising height by variably interlocking control are omitted, but when this operation button is pressed, the operation is slowed up. Alternatively, the variable operation is automatically performed up to the position of the set value together with speed control such as slowdown.

  By the way, in the electric bed 1 of the first embodiment, three state sensors 20a, 20b, and 20c are provided at the positions of the movable parts with respect to the back raising angle, the knee-lifting height, and the bed height of the landing portion 18, respectively. Is provided. Each of the state sensors 20a, 20b, and 20c can be any one of a gyro sensor, an angle sensor, an acceleration sensor, and an impact sensor for detecting a state change in one dimension or more. The sensor signals output from the three state sensors 20a, 20b, and 20c are connected to the controller 12 via respective signal cables indicated by broken lines.

  FIG. 2 shows a schematic configuration of a functional unit that realizes the operation during the entire operation of the electric bed 1 of the first embodiment. As shown in FIG. 2, an FB control unit 30 based on sensor signals from the state sensors 20a, 20b, and 20c is provided inside the controller 12.

  Referring to FIG. 2, first, an operation signal in the operation mode is output from the switch 11 to the controller 12.

  When the controller 12 receives an operation signal based on a predetermined set value relating to the back raising angle, the knee raising height, and the bed height, the controller 12 supplies a driving signal to the motor 13 and realizes a corresponding operation. A sensor signal from the state sensors 20a, 20b, and 20c is input and monitored by the function of the control unit 30, and feedback control is performed based on the sensor signal so that a state corresponding to the predetermined set value is obtained.

  The cylinders of the actuators 14 that adjust the back-raising angle, the knee-lifting height, and the bed height respectively expand and contract according to the rotation of the motor 13 and are electrically driven via the link mechanisms 16 according to the expansion and contraction. The variable operation of the landing portion 18 in the bed 10 is performed.

  Here, the state sensors 20a, 20b, and 20c are less expensive than encoders and potentiometers that are used in conventional electric beds for treatment and nursing care.

  Moreover, since the state sensors 20a, 20b, and 20c are provided at the positions of the movable parts with respect to the back raising angle, the knee-lifting height, and the bed height of the landing portion 18, the actual position of the landing portion 18 is provided. Is detected directly. For this reason, an error is absorbed between the actual position of the landing portion 18 and the rotation amount of the motor 13, and even when the landing portion 18 is deformed due to aging, the detection accuracy is hardly affected. The sensor outputs of the state sensors 20a, 20b, and 20c can be highly accurate without causing an accumulated error.

  FIG. 3 is a block diagram illustrating a schematic configuration of the FB control unit 30 in the electric bed 1 of the present embodiment. The FB control unit 30 includes a first signal input unit 31, a second signal input unit 33, a third signal input unit 33, a set value input unit 34, a signal conversion unit 35, and a comparison unit 36.

  The first signal input unit 31, the second signal input unit 33, and the third signal input unit 33 input sensor signals from the state sensors 20a, 20b, and 20c, respectively, and output them to the signal conversion unit 35.

  Based on the sensor signals from the state sensors 20a, 20b, and 20c, the signal conversion unit 35 converts into state values relating to the back raising angle, the knee-lifting height, and the bed height. The signal conversion unit 35 includes a central processing unit (CPU) and a storage unit. The signal conversion unit 35 is realized by reading a program stored in the storage unit by the CPU and executing an operation for converting the program into the state value. The signal conversion unit 35 is a table or calculation that is calibrated in advance based on the installation positions of the state sensors 20a, 20b, and 20c for conversion into state values relating to the back raising angle, knee-lifting height, and bed height. The expression is stored in the storage unit in advance, and can be immediately converted into state values relating to the back raising angle, the knee-lifting height, and the bed height based on the sensor signals from the state sensors 20a, 20b, and 20c. .

  The set value input unit 34 inputs predetermined set values related to the back raising angle, the knee-lifting height, and the bed height in the operation signal, and outputs them to the comparison unit 36.

  The comparison unit 36 compares the state value obtained from the signal conversion unit 35 with the set value obtained from the set value input unit 34, and outputs a comparison signal indicating the presence or absence of the difference.

  Therefore, the controller 12 feedback-controls the motor 13 based on the comparison signal.

(Device operation)
FIG. 4 is a flowchart showing an operation during the entire operation of the electric bed 1 according to the first embodiment of the present invention.

  First, an operation signal relating to the variable operation of the bed (landing portion 18) is transmitted from the switch 11 to the controller 12 (step S1).

  The controller 12 that has received the operation signal controls the driving of the corresponding motor 13 and drives the actuator 14 (step S2).

  At this time, the controller 12 monitors the sensor signals of the state sensors 20a, 20b, and 20c based on the comparison signal of the FB control unit 30 (step S3), and the variable operation of the bed (landing unit 18) is set to the set value. It is determined whether or not it has been reached (step S4).

  If the variable operation of the bed (landing portion 18) has not reached the set value (step S4: No), the controller 12 continues to drive the motor 13.

  On the other hand, if the controller 12 determines that the variable operation of the bed (landing portion 18) has reached the set value (step S4: Yes), the controller 12 stops driving the motor 13 and maintains the position of the actuator 14 (step S5). ).

As described above, according to the electric bed 1 of the present embodiment, it becomes feasible lower Ren a Note and precise feedback control, resulting bed itself can be cost reduction.

[Second Embodiment]
(Device configuration)
FIG. 5 is a diagram showing a schematic configuration of the electric bed 1 of the second embodiment according to the present invention. FIG. 6 is a block diagram showing a schematic configuration of a functional unit that realizes an operation during the entire operation of the electric bed 1 according to the second embodiment of the present invention. In FIGS. 5 and 6, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.

  5 and 6, the electric bed 1 according to the second embodiment of the present invention has an amount of rotation such as an encoder and a potentiometer as compared with the conventional electric bed 10 shown in FIGS. Based on the sensor signal from the state sensors 20a, 20b, and 20c, the point that the rotation amount detection sensor to detect is not provided, the points that the three state sensors 20a, 20b, and 20c are provided, and the inside of the switch 11. Although different in that a feedback (FB) control unit 30 is provided, the other components are the same.

  More specifically, similarly to the first embodiment, the electric bed 1 of the second embodiment shown in FIG. 5 has a controller 12, a motor 13, an actuator 14, and a link mechanism below a bed frame 17 that supports a human body. 16 is disposed. In particular, a total of three sets of the motor 13, the actuator 14, and the link mechanism 16 are provided so that the step-up angle, the knee-lifting height, and the bed height can be adjusted almost steplessly.

  That is, as in the first embodiment, the electric bed 1 according to the second embodiment includes three backrest angles of the landing portion 18, knee-lifting heights, and positions of movable parts with respect to the bed height. State sensors 20a, 20b, and 20c are provided. The sensor signals output from the three state sensors 20a, 20b, and 20c are connected to the controller 12 via respective signal cables indicated by broken lines.

  Similarly to the first embodiment, a harness for driving each motor 13 is connected to the controller 12. Each actuator 14 is connected to an output shaft of each motor 13, and a cylinder of each actuator 14 is connected to each link mechanism 16.

  The operation switch 11 is connected to the controller 12, and the operator uses the switch 11 to adjust the step-up angle, the knee-lifting height, and the bed height of the landing portion 18 almost steplessly. Can be done.

  Unlike the first embodiment, the controller 12 of the second embodiment can use the controller 12 as it is without changing the conventional controller 12 shown in FIGS. 10 and 12.

  The switch 11 of the present embodiment can be the same as that shown in FIG. 11 as its basic configuration. In the example shown in FIG. 11, for example, the back raising angle and the knee raising height are variably interlocked and controlled simultaneously. Although illustration of an operation button to be operated is omitted, when this operation button is pressed, a variable operation is automatically performed up to the position of the set value together with speed control such as slow-up or slow-down.

  However, the switch 11 of this embodiment is provided with an FB control unit 30 based on sensor signals from the state sensors 20a, 20b, and 20c, as shown in FIG. The configuration of the FB control unit 30 in the switch 11 of the present embodiment can be the same as that shown in FIG. 3 in the first embodiment.

  Referring to FIG. 6, first, an operation signal in the operation mode is output from the switch 11 to the controller 12.

  When the controller 12 receives an operation signal based on a predetermined set value related to the back raising angle, the knee raising height, and the bed height, the controller 12 supplies a driving signal to the motor 13 in order to realize a corresponding operation.

  The cylinders of the actuators 14 that adjust the back-raising angle, the knee-lifting height, and the bed height respectively expand and contract according to the rotation of the motor 13 and are electrically driven via the link mechanisms 16 according to the expansion and contraction. The variable operation of the landing portion 18 in the bed 10 is performed.

  The switch 11 inputs and monitors the sensor signals from the state sensors 20a, 20b, and 20c by the function of the FB control unit 30, and performs feedback control so as to be in a state corresponding to the predetermined set value based on the sensor signals. Do.

  As described above, the state sensors 20a, 20b, and 20c are less expensive than encoders and potentiometers that are used in conventional electric beds for treatment and nursing care.

  Moreover, since the state sensors 20a, 20b, and 20c are provided at the positions of the movable parts with respect to the back raising angle, the knee-lifting height, and the bed height of the landing portion 18, the actual position of the landing portion 18 is provided. Is detected directly. For this reason, an error is absorbed between the actual position of the landing portion 18 and the rotation amount of the motor 13, and even when the landing portion 18 is deformed due to aging, the detection accuracy is hardly affected. The sensor outputs of the state sensors 20a, 20b, and 20c can be highly accurate without causing an accumulated error.

(Device operation)
FIG. 7 is a flowchart showing an operation during the entire operation of the electric bed 1 according to the second embodiment of the present invention.

  First, an operation signal relating to the variable operation of the bed (landing portion 18) is transmitted from the switch 11 to the controller 12 (step S11).

  The controller 12 that has received the operation signal controls the driving of the corresponding motor 13 and drives the actuator 14 (step S12).

  At this time, the switch 11 monitors the sensor signals of the state sensors 20a, 20b, and 20c based on the comparison signal of the FB control unit 30 (step S13), and the variable operation of the bed (landing unit 18) is set to the set value. It is determined whether or not it has been reached (step S14).

  If the variable operation of the bed (landing portion 18) has not reached the set value (step S14: No), the switch 11 does not transmit an operation signal for stopping the driving of the motor 13 and continues the driving. .

  On the other hand, when the switch 11 determines that the variable operation of the bed (landing portion 18) has reached the set value (step S14: Yes), the switch 11 transmits an operation signal for stopping the drive of the motor 13 to the controller 12 ( Step S15).

  The controller 12 receives the operation signal, stops driving the motor 13, and holds the position of the actuator 14 (step S16).

As described above, according to the electric bed 1 of the present embodiment, it becomes feasible lower Ren a Note and precise feedback control, resulting bed itself can be cost reduction.

  In addition, the electric bed 1 of the second embodiment is the second type by replacing the switch 11 and installing the state sensors 20a, 20b, and 20c with respect to the existing first type electric bed that does not perform feedback control. The electric bed can be transformed into a second type electric bed at a lower cost than purchasing a new electric bed.

  In addition, the electric bed 1 of the second embodiment is a switch of the switch 11 for the existing second type electric bed that performs feedback control based on a rotation amount detection sensor that detects the rotation amount of an encoder, a potentiometer, or the like. By simply installing the state sensors 20a, 20b, and 20c, it can be transformed into the second type electric bed with higher accuracy.

  The present invention has been described above with reference to specific embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical concept thereof. For example, in the example of each embodiment described above, an example in which three state sensors 20a, 20b, and 20c are provided at the positions of the movable portions with respect to the back raising angle, the knee raising height, and the bed height of the landing portion 18, respectively. However, this is a preferred example, and it is only necessary to provide two state sensors 20a and 20b at the positions of the movable parts with respect to the back raising angle and knee raising height of the landing part 18, respectively. Feedback control is possible for the back-raising angle, knee-lifting height, and bed height. In particular, the state sensors 20a, 20b, and 20c used for feedback control according to the present invention can be any of a gyro sensor, an angle sensor, an acceleration sensor, and an impact sensor. It is preferable to arrange a plurality of one-dimensional positions corresponding to the undulation operations such as the bed height and to detect a state change related to the undulation operations in two or more dimensions. For this reason, the present invention can be a single state sensor for an electric bed that performs one type of hoisting operation, or a common movable part for an electric bed that performs three or more types of hoisting operations. Can be made cheaper by using a single state sensor.

  Moreover, in the example of the embodiment described above, the example in which the state sensors 20a, 20b, and 20c are provided in the landing portion 18 has been described. However, for example, in the movable portion related to the movement of the landing portion 18 such as the link mechanism 16 and the actuator 14. If there is, it can be installed at any location.

  Further, in the example of the embodiment described above, an example in which the actuator 14 by the motor 13 is used as a drive mechanism has been described. However, this is a preferable example for performing fine interlocking control, and a hydraulic or pneumatic actuator, It can also be set as the electric bed which uses another drive mechanism.

  Further, the electric bed according to the present invention may be configured to transmit an operation signal of the switch 11 to the controller 12 by wire or wirelessly.

(Status sensor)
As described above, the state sensors (three state sensors 20a, 20b, and 20c in this example) used for feedback control according to the present invention can detect a one-dimensional or multi-dimensional state change, and can increase the back angle and the knee height. The position corresponding to each undulation operation such as the bed height and the like can be detected. In particular, in order to detect the position corresponding to the undulation operation, it is preferable to use a sensor that can detect the inclination of the movable part where the state sensor is installed with respect to the absolute coordinate axis. Further, as will be described below, as the state sensors (three state sensors 20a, 20b, 20c in this example) used for feedback control according to the present invention, two or more absolute coordinate axes (for example, xyz axes) It is more preferable to use a sensor that can detect the inclination of the movable part corresponding to each axis (for example, the xy axis) with respect to the xy axis. For this reason, a gyro sensor, an angle sensor, an acceleration sensor, an impact sensor, or the like can be used as the state sensor.

  As a precaution, these specific sensors will be described. First, the gyro sensor is also called a rotational angular velocity sensor, and there are various mechanisms such as a vibration type, a geomagnetic type, an optical type, a thermal type, or a mechanical type. However, as the most commonly installed in consumer devices, there is one type of IC type (one-dimensional such as up / down, left / right, and front / rear) and three axes (three-dimensional xyz axis such as up / down, left / right, and front / rear) There is a vibration type gyro sensor, and this vibration type gyro sensor includes a capacitance method using silicon and a piezoelectric method using crystal and other piezoelectric materials. A vibratory gyro sensor is a combination of an element that moves mechanically in response to movement (state change) and an electronic circuit that processes signals based on the movement of the element. , Movement (state change) can be detected. Therefore, it can be configured as a state sensor that detects a state of a plurality of axes (multiple dimensions) by using a plurality of three-axis gyro sensors or one-axis gyro sensors.

  The angle sensor is a so-called uniaxial gyro sensor. Generally, the angle sensor emits a magnetic field or light when a rotating body that rotates according to movement (state change) and a slit provided in the rotating body pass through. Processes signals based on the same principle as a rotary encoder that combines an electronic circuit that detects blocking, a capacitive film that changes its capacitance according to movement (change in state), and a signal based on the change in capacitance There is a combination with an electronic circuit that performs this, and by detecting such a change in the rotating body or change in capacitance, it is possible to detect movement (state change). Therefore, it can be configured as a state sensor that detects a plurality of axes (multiple dimensions) using a plurality of single-axis angle sensors.

  In addition, there are various types of acceleration sensors such as vibration type, geomagnetic type, optical type, thermal type, and mechanical type, which may be treated as a kind of gyro sensor. , Right and left or front and back one-dimensional) and acceleration in each axis direction in three axes (up and down, left and right, front and rear three-dimensional), and the operation principle is different only in the processing of the electronic circuit. It is the same as the gyro sensor. Accelerometers are most commonly installed in consumer equipment, and include IC type 1 axis (one-dimensional such as up / down, left / right, front / rear) and 3 axes (up / down, left / right, front / rear xyz axis 3). In particular, in mobile phones and the like, the inclination of the mobile phone is detected by measuring the gravitational acceleration of the earth so that the screen is always displayed in the correct orientation. Therefore, it can be configured as a state sensor that detects a state of a plurality of axes (multiple dimensions) using a plurality of three-axis acceleration sensors and a plurality of one-axis acceleration sensors.

  The impact sensor is sometimes treated as a kind of acceleration sensor. Strictly speaking, a magnet that moves in response to movement (state change) and an electronic circuit that processes a signal indicating acceleration based on the movement of the magnet are included. It is a combination and is configured to simply output the strength of impact generated at the sensor site. A plurality of such single-axis impact sensors can be used to form a state sensor that detects the state of multiple axes (multiple dimensions).

  As a state sensor (three state sensors 20a, 20b, 20c in this example) used for feedback control according to the present invention, one axis (one-dimensional such as up / down, left / right or front / rear) or three axes (up / down, left / right, Various sensors can be used as long as they can output signals indicating the state change in the axial direction of the xyz axis such as front and rear, as well as those that can be converted into state changes in the axial direction.

  However, the above-described gyro sensor, angle sensor, acceleration sensor, or impact sensor is advantageous from the viewpoint of cost reduction because it is widely used for consumer use. In particular, the gyro sensor and the acceleration sensor are widely used. In addition, it is highly accurate and suitable not only for cost reduction but also for high accuracy feedback control according to the present invention.

  By the way, in order to enable position control corresponding to the raising / lowering operations such as the back raising angle, the knee raising height, and the bed height, the control may be performed at an angle corresponding to the raising / lowering operation. For this reason, the feedback control according to the present invention can be configured only by detecting a state change of one axis (one-dimensional such as up / down, left / right, or front / rear). However, the position control in the feedback control according to the present invention becomes more accurate by using the detection of the multi-dimensional state change to perform the position control corresponding to the undulation operation. Since this point has been verified, it will be described below.

  Experimentally, as for the state sensor 20a, when a 3-axis acceleration sensor is used and position control in feedback control is performed by detecting a change in the state of one axis among the three-axis output signals, the output signal of the three axes Among these, the error with respect to the case where the position control in the feedback control was performed by detecting the state change of the two axes was verified.

  FIG. 8 is a principle diagram when angle detection is performed biaxially for a state sensor used for feedback control according to the present invention. As shown in FIG. 8, when the acceleration sensor is inclined at an angle θ with respect to absolute coordinates (x-axis: horizontal direction, y-axis: vertical direction), ax and ay are the sensor axes. Since the obtained biaxial output signals Sx and Sy are obtained as signals of gravity (G) components corresponding to the angle θ, the angle θ can be detected from each of the output signals Sx and Sy.

  For example, when the angle θ is detected from the output signal Sx, gravity (G) at cos 0 ° (x axis) is 1 G, 0.9998 G at cos 1 °, 0.7071 G at cos 45 °, cos 89 When it is °, it is 0.0175 G, and when it is cos 90 °, it is 0 G.

  As the cos angle increases to 0 °, 1 °, 45 °, 89 °, and 90 °, gravity decreases to 1G, 0.9998G, 0.7071G, 0.0175G, and 0G. The difference in the change amount from cos 0 ° to cos 1 ° is 0.0002, the difference in the change amount from cos 89 ° to cos 90 ° is 0.9825, and the difference in the change amount increases as G decreases.

  On the other hand, when the angle θ is detected from the output signal Sy, gravity (G) at sin 0 ° (y axis) is 0 G, 0.0175 G at sin 1 °, 0.7071 G at sin 45 °, When it is sin 89 °, it becomes 0.9998G, and when it is sin 90 °, it becomes 1G. As the sin angle increases to 0 °, 1 °, 45 °, 89 °, and 90 °, gravity increases to 0G, 0.0175G, 0.7071G, 0.9998G, and 1G. The difference in change from sin 0 ° to 1 ° is 0.9825, and the difference in change from sin 89 ° to sin 90 ° is 0.0002. As G increases, the difference in change becomes smaller.

(For single-axis feedback control)
Table 1 shows data actually measured for one-axis (one-dimensional) feedback control. As understood from Table 1, an angle (x (cos) sensor angle) detected by the cos calculation from the output signal Sx, and an angle (y (sin) sensor angle) detected by the sin calculation from the output signal Sy When only the x-axis is used for one axis (one dimension), the difference in the amount of change increases at cos 90 ° and the accuracy increases, and the difference decreases at cos 0 ° and the accuracy tends to decrease. It has become. Further, when only the y-axis is used for one axis (one dimension), the difference increases and the accuracy increases at 0 °, and the difference decreases and the accuracy decreases at sin 90 °. Therefore, in the case of single-axis feedback control using only one of the sensor axes ax and ay, the error is less than 3 °, but the accuracy is uneven. In particular, in the case of feedback control using only the sensor axis ax, horizontal In the vicinity, there is a phenomenon in which the influence of resolution increases and the accuracy decreases compared to other angular regions.

(For 2-axis feedback control)
On the other hand, Table 2 shows data actually measured for two-axis (two-dimensional) feedback control. As can be seen from Table 2, when the two axes are used, the difference in the amount of change from cos 0 ° to cos 1 ° decreases to 0.0002, but the accuracy decreases from sin 0 ° to sin 1 °, which is 0.9825. Goes up. In addition, the difference in the amount of change from sin 89 ° to sin 90 ° is 0.0002, and the accuracy is lowered. However, the difference in the amount of change from cos 89 ° to cos 90 ° is 0.9825, and the accuracy is increased. As understood from Table 2, an angle (x (cos) sensor angle) detected from the output signal Sx by the cos calculation, and an angle detected by the sin calculation from the output signal Sy (y (sin) sensor angle) Since the accuracy with respect to the actual angle is symmetric, the accuracy of the “y (sin) sensor angle” is increased in the range where the accuracy decreases with the “x (cos) sensor angle”, and the accuracy of “y (sin ) The accuracy of the “x (cos) sensor angle” increases in the range of the angle where the accuracy decreases by “sensor angle”. Therefore, the y-axis output signal Sy can be supplemented by the y-axis output signal Sy because the y-axis accuracy is good in the range of the gravity component with poor accuracy in the x-axis output signal Sx. Then, since the accuracy of the x-axis is good and can be compensated by the output signal Sx of the x-axis, unevenness in accuracy can be suppressed.

  Based on the actual measurement results in Tables 1 and 2, FIG. 9 shows a case where the feedback control according to the present invention performs the feedback control only with the x axis (one-dimensional) at the actual angle θ = 0 to 70 °. The distribution of each angular error when feedback control is performed only on the axis (one dimension) and when feedback control is performed on the x and y axes (two dimensions) is schematically shown.

  As can be understood from FIG. 9, the 2-axis (two-dimensional) feedback control can suppress the non-uniformity of accuracy regardless of the range of the actual angle θ, and the single-axis (one-dimensional) feedback control. In addition, the accuracy with respect to position control can be further improved (in the experiment, the error is 0.6 ° or less).

  Therefore, in the feedback control according to the present invention, as the number of dimensions of the state sensor is increased, the accuracy with respect to the position control is further improved, so that each undulation operation such as the back raising angle, the knee raising height, and the bed height is performed. For corresponding position control, it is preferable to detect a change in state in a plurality of dimensions rather than one dimension.

According to the present invention is useful for more it is possible to configure an electric bed which allows realizing a lower Ren a Note and precise feedback control of the electric bed for therapeutic or nursing applications.

DESCRIPTION OF SYMBOLS 1 Electric bed of this invention 10 Conventional 2nd type electric bed 11 Switch 12 Controller 13 Motor 14 Actuator 15 Rotation amount detection sensor (encoder or potentiometer)
16 Link mechanism 17 Bed frame 18 Landing unit 20a, 20b, 20c State sensor 30 Feedback (FB) control unit 31 First signal input unit 32 Second signal input unit 33 Third signal input unit 34 Set value input unit 35 Signal conversion Part 36 Comparison part 111 Setting value display part 112 Operation / setting button part 111a, 111b, 111c Setting display part 112a, 112b, 112c Up / down button 112d Setting button 112e Operation button 112f, 112g LED display part

Claims (5)

An electric bed that can control the undulation motion by feedback control,
A switch for generating an operation signal based on a predetermined set value for performing a predetermined undulation operation on the landing portion;
A controller that receives the operation signal in a wired or wireless manner and controls a drive mechanism that performs the predetermined undulation operation on the landing portion;
A state sensor installed at a movable part related to the movement of the landing part,
Either one of the switch or the controller is provided with a feedback control unit that feedback-controls execution of the predetermined undulation operation by the drive mechanism based on a sensor signal from the state sensor,
The feedback control unit may have a row the feedback control while monitoring the sensor signal from the state sensor to be a state corresponding to the predetermined set value,
The predetermined undulation operation comprises two or more types of undulation operations,
One of the state sensors is provided at a common movable part in the two or more types of undulation operations, and is installed in a number smaller than the number of types of the predetermined undulation operations . The electric bed according to claim 1 , wherein the driving mechanism includes an actuator driven by a motor. The condition sensor is characterized in that for the absolute coordinate axes consisting detectable sensor a tilt of the movable portion, an electric bed according to claim 1 or 2. The electric motor according to any one of claims 1 to 3 , wherein the state sensor includes a sensor capable of detecting an inclination of the movable part corresponding to each axis with respect to two or more absolute coordinate axes. bed. The electric bed according to any one of claims 1 to 4 , wherein the state sensor includes a gyro sensor, an angle sensor, an acceleration sensor, or an impact sensor.