JP7188702B2 - power assist suit - Google Patents

Description

The present disclosure relates to power assist suits.

Wearable mobile machines, which are exoskeleton-type or clothing-type devices worn on the human body, are known. Such wearable mobile machines, also called power assist suits or powered exoskeleton, use power such as electric actuators, artificial muscles, etc. to generate the force of human limbs and the sustaining power of that force. can be enhanced.

The power assist suit has actuator units at positions corresponding to each joint of the human body. The actuator unit includes an electric actuator, a drive circuit for controlling the electric actuator, and the like. A control unit is also provided to control the operation of each electric actuator.

A single power assist suit can be provided with dozens of actuator units. Since the control unit communicates with each actuator unit on a one-to-one basis to control the driving of each actuator, the load on the control unit is large. If the power assist suit is to perform more complex movements or implement new functions, the load on the control unit will be even higher. The heavy load imposed on the control unit will hinder future enhancement of functionality and added value of power assist suits.

WO2006/088966 discloses a system in which a plurality of mechatronic devices communicate with each other to control the movement of a human limb.

WO2006/088966

In order to reduce the processing load of the control unit, it is necessary to fully consider how the control unit and the actuator unit should be linked and what kind of operation the actuator unit should perform.

The present disclosure provides techniques for distributing processing to the control unit and actuator unit of the power assist suit to avoid concentration of load on the control unit.

A power assist suit according to an exemplary embodiment of the present disclosure has a control unit and a plurality of actuator units respectively provided at a plurality of joints, between the control unit and each actuator unit, and , a power assist suit in which the plurality of actuator units are communicably connected to each other via a communication network, wherein the control unit has a communication circuit and a control circuit; and the plurality of actuator units are connected to a first actuator unit and a second actuator unit, each of said first actuator unit and second actuator unit comprising: a processing circuit for generating a control signal; an actuator; a drive circuit for driving said actuator according to said control signal; each has a storage device storing a plurality of operation parameters for operating the actuator, and a communication circuit for transmitting and receiving data frames between the control unit and other actuator units, The control unit transmits a command designating a predetermined operation mode to the first actuator unit and the second actuator unit, and in the first actuator unit having received the command , the processing circuit receives the command from the storage device. reading the plurality of operating parameters corresponding to the designated predetermined operating mode, receiving an assist command from the second actuator unit, and utilizing the plurality of operating parameters in response to receiving the assist command. generating a first control signal that is the control signal, causing the drive circuit to drive the actuator according to the first control signal, transmitting an assist command to the second actuator unit at a first timing, and receiving the command ; In the second actuator unit, the processing circuit reads the plurality of operation parameters corresponding to the designated predetermined operation mode from the storage device, receives an assist command from the first actuator unit, and generating a second control signal that is the control signal using the plurality of operation parameters in response to receiving the command, causing the drive circuit to drive the actuator by the second control signal, and assisting at a second timing; sending a command to the first actuator unit, the storage storing the actuator angle and assist as one of the plurality of operating parameters; The processing circuit stores angle-torque data associated with the magnitude of torque, obtains angle data indicating the rotation angle of the actuator, and refers to the angle-torque data based on the angle data to obtain the angle-torque data. Determines the magnitude of the assist torque.
A power assist suit according to an exemplary embodiment of the present disclosure has a control unit and a plurality of actuator units respectively provided at a plurality of joints, between the control unit and each actuator unit, and , a power assist suit in which the plurality of actuator units are communicably connected to each other via a communication network, wherein the control unit has a communication circuit and a control circuit; and the plurality of actuator units are connected to a first actuator unit and a second actuator unit, each of said first actuator unit and said second actuator unit comprising: a processing circuit for generating a control signal; an actuator; a drive circuit for driving said actuator according to said control signal; Each mode has a storage device storing a plurality of operation parameters for operating the actuator, and a communication circuit for transmitting and receiving data frames between the control unit and other actuator units. , the control unit transmits a command designating a predetermined operation mode to the first actuator unit and the second actuator unit, and in the first actuator unit receiving the command, the processing circuit stores the memory device , reads out the plurality of operating parameters corresponding to the designated predetermined operating mode from, receives an assist command from the second actuator unit, and utilizes the plurality of operating parameters in response to receiving the assist command. generates a first control signal that is the control signal, causes the drive circuit to drive the actuator by the first control signal, transmits an assist command to the second actuator unit at a first timing, and receives the command. In the second actuator unit, the processing circuit reads the plurality of operation parameters corresponding to the specified predetermined operation mode from the storage device, receives an assist command from the first actuator unit, and generating a second control signal, which is the control signal, by using the plurality of operation parameters in response to receiving the assist command; causing the drive circuit to drive the actuator according to the second control signal; An assist command is transmitted to the first actuator unit, and the first timing is the rotation angle of the actuator of the first actuator unit and the first actuator unit. The second timing is determined according to a relationship with a threshold, and the second timing is determined according to a relationship between the rotation angle of the actuator of the second actuator unit and the second threshold.

In the power assist suit according to the exemplary embodiment of the present disclosure, the control unit sends a command specifying a predetermined operation mode to each actuator unit, and each actuator unit that receives the command communicates with each other. while driving its own actuator. This makes it possible to realize one operation of the power assist suit as a whole while reducing the load on the control unit.

FIG. 1A is a diagram showing the structure of a data frame 1a used in wired serial communication. FIG. 1B is a diagram showing the structure of a data frame 1b used in wireless communication. FIG. 2 is a diagram showing the common data structure 12. As shown in FIG. FIG. 3 is a diagram showing the appearance of the power assist suit 30. As shown in FIG. FIG. 4 is a schematic diagram of the configuration of the power assist suit 30 in which the actuator units 32a-32e communicate with each other. FIG. 5 is a diagram showing a configuration example of the control unit of the power assist suit 30 and the two motor units that drive the hip joints. FIG. 6A is a diagram showing an example of angle-torque data. FIG. 6B is a diagram showing another example of angle-torque data. FIG. 7 is a diagram showing an example of a data frame 2a during RS-485 standard communication. FIG. 8 is a diagram showing the relationship between the rotation angle of each actuator provided in the left and right actuator units 106A and 106B and time during forward walking. FIG. 9 is a diagram showing coordinated operations during assist operations realized by mutual communication between actuator units 106A and 106B. FIG. 10 is a diagram showing an example of a data frame 2a transmitted from the right actuator unit 106B to the left actuator unit 106A. FIG. 11 is a timing chart showing the relationship between the operation timings of the control unit 150, the left actuator unit 106A, and the right actuator unit 106B. FIG. 12 is a flow chart showing the procedure of processing executed by the control circuit 154 of the control unit 150. As shown in FIG. FIG. 13 is a flow chart showing the procedure of processing executed by the processor 112B of the right actuator unit 106B. FIG. 14 is a flow chart showing the procedure of processing executed by the processor 112A of the left actuator unit 106A.

An example of a power assist suit according to the present disclosure will now be described with reference to the accompanying drawings. Note that more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art. The inventors provide the accompanying drawings and the following description for a full understanding of the present disclosure by those skilled in the art. They are not intended to limit the claimed subject matter.

A power assist suit according to an exemplary embodiment of the present disclosure has a control unit and a plurality of actuator units respectively provided at a plurality of joints. A communication network connects the control unit and each actuator unit and between the plurality of actuator units so as to be able to communicate with each other. When the power-assist suit is worn by a person, the power-assist suit assists with the force required for activities such as walking, lifting and unloading.

In this embodiment, the control unit does not always control the operation of all actuator units. The control unit initially instructs each actuator unit what action to take, but the subsequent actions are communicated by the actuator units. In other words, the control unit and each actuator unit communicate with each other in a so-called server-client system at the start of operation. After the start of operation, a plurality of actuator units communicate in a peer-to-peer manner and operate simultaneously in parallel. This allows the power assist suit as a whole to achieve one movement. Also, a person wearing a power assist suit can perform a desired movement with increased force.

The following description describes the communication protocol according to the present embodiment, followed by a detailed description of the configuration and operation of the power assist suit.

1. Communication Protocol Used in Power Assist Suit FIG. 1A shows the structure of a data frame 1a used in wired serial communication. An example of serial communication assumes RS-485 standard communication. The RS-485 standard establishes electrical specifications for the physical layer referred to in the OSI reference model.

The data frame 1a contains various data. For reference, the top row of FIG. 1A shows the division of each layer of the OSI reference model. The data size of each data is indicated in bytes at the bottom of FIG. 1A. The leftmost column of FIG. 1A is a legend. The same applies to FIGS. 1B and 2, which will be described later.

The data frame 1a includes, for example, a source device ID 10, a destination device ID 11, and a common data structure 12. FIG. The transmission source device ID 10 is an identifier that identifies the transmission source device. The destination device ID 11 is an identifier for identifying a destination device. The identifier is, for example, an ID (device identifier or device ID) assigned to each device without duplication at the time of manufacture. A device ID is an identifier that uniquely indicates an actuator unit within a communication network. The common data structure 12 is a data structure containing one or two commands which will be described later.

Until now, in order to control each actuator such as a power assist suit, it was sufficient to have only a destination device ID that identifies the actuator to be controlled. This is because if the control unit functioning as a server in the server-client system specified a destination device ID and sent command and control data, the actuator would operate according to the command and control data. However, as described above, the processing load on the control unit is increasing, so there is a growing need to break away from the control method based solely on the server/client system.

The present inventor has studied construction of a system (power assist suit) in which a plurality of actuators communicate with each other and operate organically as a whole, which has not been considered before. Therefore, a communication protocol provided with a source device ID 10 and a common data structure 12 has been adopted.

FIG. 1B shows the structure of a data frame 1b used in wireless communication. As an example of wireless communication, Wi-Fi (registered trademark; the same shall apply hereinafter) standard communication is assumed. The Wi-Fi standard establishes specifications for the physical layer and data link layer referred to in the OSI reference model.

The data frame 1b includes multiple headers for each layer of the OSI reference model. Originally, the IP header is supposed to store the destination IP address 20 and the source IP address 21 . The inventor considered that the source IP address 21 can be used as an identifier corresponding to the source device ID 10 described above. Therefore, the transmission source IP address 21 is used in the communication protocol that uses the common data structure 12 of the Wi-Fi standard.

Note that the above-described wired communication and wireless communication are examples. Any other communication protocol can be used. For example, when a source IP address is used as a source device, the IP address belongs to the network layer in the OSI reference model, so lower layers such as the physical layer and the data link layer are optional.

The inventor constructed a power assist suit that realizes communication between actuators by using an identifier that uniquely indicates a transmission source within a communication network. The present disclosure is applicable as long as the header or the like contains an identifier that uniquely indicates the source. Even an existing communication protocol can be used for communication between actuator units as an identifier corresponding to the source device ID 10 as long as it contains an identifier indicating a source. For example, in Ethernet (registered trademark) standard communication, a MAC (Media Access Control) address is used as an identifier representing a source device. A MAC address may be used as a source device ID according to the present disclosure.

FIG. 2 shows common data structure 12 .

The common data structure 12 has a data length field 12a, an action-related command field 12b, an attribute-related command field 12c, and a data field 12d.

The data length field 12a indicates the total number of bytes of the common data structure 12. FIG.

The motion system command field 12b indicates a motion system command for operating an actuator, for example. An action-related command is described by a numerical value (binary notation) corresponding to the action-related command. Examples of operational commands are Write Data, Read Data, Execution, Connect, Multicast, and Start Operation. Write data, read data, etc. are operations performed by the actuator unit.

The attribute-based command field 12c indicates an attribute-based command designating an attribute related to the actuator. Attribute-based commands are also described by numerical values (binary notation) corresponding to the commands. Examples of attribute-based commands are present angle, target torque, angle limit, serial number, and control mode designation. Attribute-based commands can be said to be static or dynamic attributes about actuators that are specified along with motion-based commands.

For example, "control mode designation" indicates the operation mode of the power assist suit, which will be described later. Specifically, operation modes such as release, forward walking, backward walking, lifting, loading and unloading, etc. can be specified.

The data field 12d describes data for the attribute-based command field 12c. Examples of data are torque setpoints, rotational speed setpoints, and serial number values.

The common data structures described above have relatively short data lengths, for example in the range of 3 bytes to 13 bytes. Since EtherCAT, which is another communication protocol, has a size of 32 bytes, it is possible to eliminate mixture during communication and to suppress occupation of lines. Furthermore, since the action-related commands and the attribute-related commands are specified separately, it is easy for the user (program creator) to understand.

The commands stored in the action-related command field 12b and the attribute-related command field 12c will be described later.

2. Configuration of Power Assist Suit Next, an exemplary embodiment of a power assist suit and an actuator unit that constitutes the power assist suit will be described.

For example, FIG. 3 shows the appearance of a power assist suit 30 equipped with a plurality of actuator units. The power assist suit 30 can be used for agricultural work, nursing work, and the like. About 20 or more actuator units can be attached to one power assist suit 30 to support the strength of the arms and legs. This enables the power assist suit 30 to realize complex movements. Incidentally, in this embodiment, the actuator is an electric motor.

An actuator unit is mounted at each position indicated by an arrow on the power assist suit 30 . By way of example, the positions of actuator units 106A and 106B, which will be explained later, are shown. The position and number of actuator units is an example. For reference, FIG. 3 shows a silhouette of a person wearing the power assist suit 30 (hereinafter referred to as "wearer").

FIG. 4 is a schematic diagram of the configuration of the power assist suit 30 according to the present embodiment, in which a plurality of actuator units 32a-32e communicate with each other. Actuator units that communicate with each other are connected by lines. As described below, each actuator unit includes an actuator and various circuit elements.

For example, the actuator units 32a to 32e are provided at the waist, the hip joint of the right leg, the knee of the right leg, the knee of the left leg, and the hip joint of the thigh of the left leg, respectively. Each actuator unit 32 a - 32 e starts operating according to instructions from the control unit 150 . The actuator unit 32a expands and contracts the waist. The actuator unit 32b lifts the thigh of the right leg forward and sends it backward. The actuator unit 32c extends and contracts the knee of the right leg. The actuator unit 32d extends and contracts the knee of the left leg. The actuator unit 32e lifts the thigh of the left leg forward and sends it backward.

In order to realize communication between actuator units as described above, each actuator unit grasps from which actuator unit of many actuator units the command is received and to which actuator unit the command should be sent. There is a need to. Therefore, the “source device ID 10” or “source IP address 21” shown in FIG. 1A can be used as data indicating the source. The “source device ID 10” or “source IP address 21” can also be used as a destination for sending a response to a received command.

The configuration of the actuator units and communication between the actuator units will be described below.

FIG. 5 shows a configuration example of two left and right actuator units 106A and 106B provided at the hip joint of the power assist suit 30 according to this embodiment. For convenience of explanation, only two actuator units 106A and 106B are shown in the example of FIG. 5, but there may be three or more as shown in FIGS.

The actuator unit 106A has a communication circuit 110A, a processor 112A, a memory 113A, a drive circuit 114A, a joint actuator 116A, and a joint mechanism 104A. The actuator unit 106B has a communication circuit 110B, a processor 112B, a memory 113B, a drive circuit 114B, a joint actuator 116B and a joint mechanism 104B. The actuator units 106A and 106B are sometimes called intelligent motors (registered trademark). In the above description, as an example, the joint mechanisms 104A and 104B are included in the actuator units 106A and 106B, respectively, but they do not have to be included.

In this specification, the actuator units 106A and 106B also communicate with the control unit 150 shown in FIG.

FIG. 5 shows a communication circuit 152 and a control circuit 154 which are components of the control unit 150 . The communication circuit 152 generates data frames and transmits them to other actuator units. The control circuit 154 is a so-called microcomputer or signal processor, and generates a predetermined operation mode and an operation start instruction for each actuator unit. Each function of the communication circuit 152 and the control circuit 154 will be described later.

Next, the configuration of actuator units 106A and 106B will be described.

Communication circuits 110A and 110B have buffers 111A and 111B, respectively. Identifiers for identifying actuator units 106A and 106B are stored in advance in buffers 111A and 111B. The identifier may be letters and/or numbers that can be uniquely identified within a communication network within a communicable range, such as an IP address or an ID given to each device without duplication (device identifier or Device ID).

When a data frame is received, communication circuits 110A and 110B perform physical layer and data link layer processing, respectively, and transmit destination device ID 11 (FIG. 1A) of the data frame as an identifier stored in buffers 111A and 111B. Determines whether or not it matches its own identifier. If so, communication circuits 110A and 110B continue processing the data frame. Even if they do not match, the communication circuits 110A and 110B continue processing the data frame even if a special identifier (for example, 0xFF) specifying all identifiers as destinations is described. If none match, communication circuits 110A and 110B discard the data frame.

When wireless communication is performed according to the Wi-Fi standard, an IP address can be adopted as the identifier of itself. Communication circuits 110A and 110B determine whether the destination IP address 20 (FIG. 1B) of the data frame matches its own IP address or a multicast address specifying all identifiers as destinations. do it. Subsequent processing is the same as the processing described above.

When continuing to process the data frame, the communication circuits 110A and 110B sequentially process the data frame for each IP layer, transport layer, etc. in the OSI reference model, and extract the common data structure 12 . As described above, the common data structure 12 includes the operational command field 12b and the like. Communication circuits 110A and 110B extract and transmit commands to processors 112A and 112B, respectively.

Both of the processors 112A and 112B are semiconductor integrated signal processors. Processors are also called "processing circuits." Processors 112A and 112B generate control signals to rotate actuators 116A and 116B at specified torques, respectively. The control signal is, for example, a PWM signal. The processors 112A and 112B also interpret commands and data contained in the common data structure 12 contained in data frames transmitted from other actuator units, and perform processing according to the contents of the commands.

The memories 113A and 113B hold in advance a table that associates other actuator units with identifiers of the actuator units. That is, an identifier is preset in the communication circuit of each actuator unit, and the identifier is held in the memory of the other actuator units. Once the actuator units to which data frames are to be transmitted/received are determined, the processors 112A and 112B can specify the identifiers of the actuator units and instruct the communication circuits 110A and 110B.

Further, memories 113A and 113B store a plurality of prepared operating parameters. "Operating parameters" are parameters for operating actuators 116A and 116B, respectively. Operation parameters can be prepared for each operation mode of the power assist suit 30 . An example of a mode of operation is release mode of operation, walk forward, walk backward, lift load, unload load. "Releasing the operation mode" means canceling or ending the operation mode such as forward walking.

Examples of operating parameters for each operating mode include, for example, clockwise (CW) upper speed limit, counterclockwise (CCW) upper speed limit, CW upper torque limit, CCW upper torque limit, operating speed, operating torque, trigger angle, These are the trigger direction, the destination ID, the proportional gain, the integral gain, and the differential gain. Table 1 below shows each operating parameter that can be set for the advance direction. Similar operating parameters may be set for backward travel, lift and load/unload modes of operation. The correspondence between operating modes and operating parameters shown in Table 1 is referred to herein as a "lookup table".

Additionally, the operating parameters may include angle-torque data for each operating mode. The angle-torque data is data in which the angle of the actuator and the magnitude of the assist torque are associated with each other. The angle-torque data can be provided in the form of functions, tables, or the like.

In this embodiment, the memories 113A and 113B are assumed to be random access memories (RAM), for example, but any storage device may be used. For example, it may be a semiconductor storage device such as a flash memory, a magnetic storage device such as a hard disk drive, or an optical recording device using an optical disk.

6A and 6B show an example of angle-torque data expressed in functional form. In this embodiment, the magnitude of the torque (required torque) Tq0 required for operation is proportional to the angle. The assist torque Tq1 indicates the magnitude of torque produced by each actuator.

In FIG. 6A, Tq1 is obtained by a proportional calculation in which the required torque Tq0 is multiplied by a coefficient. In this case, the larger the angle, the larger the difference between the assist torque Tq1 and the required torque Tq. In other words, the greater the angle, the more torque needs to be generated by human power.

Therefore, it may be preferable to generate the assist torque Tq1 such that the difference in magnitude between the assist torque Tq1 and the required torque Tq is approximately constant, as shown in FIG. 6B. According to the example of FIG. 6B, the torque to be generated by human power is constant regardless of the angle, and the burden on the wearer of the power assist suit 30 can be reduced.

In both examples of FIGS. 6A and 6B, the assist torque of the actuator is set to zero when the rotation angle of the actuator is within a predetermined angle range R including 0 degree. That is, the angle range R is a dead area in which no assist torque is generated regardless of the angle. The reason for providing the dead area is that when the rotation angle vibrates between positive and negative in the vicinity of 0 degrees, the positive and negative assist torque Tq1 is applied while alternating, and the operation of the power assist suit 30 becomes unstable. Because it becomes In addition, it is possible to prevent the battery from being exhausted by preventing unnecessary operations in the idle state.

In this embodiment, a difference is provided between the required torque Tq0 and the assist torque Tq1, but the difference may be zero. That is, the assist torque Tq1 may be made equal to the required torque Tq0. An example in which the required torque Tq0 and the assist torque Tq1 are in a proportional relationship has been given, but the proportional relationship is merely an example, and other relationships may be given.

Refer to FIG. 5 again.

Drive circuits 114A and 114B apply current to actuators 116A and 116B, respectively, with a magnitude and direction dependent on the PWM signal. This causes actuators 116A and 116B to generate clockwise or counterclockwise torque. As the actuator rotates, the joint mechanisms 104A and 104B attached to the rotary shaft of the actuator also rotate clockwise or counterclockwise. As a result, the joint mechanism operates at a speed, angle and direction according to the rotation of the actuator.

Torque and time to be generated, etc., can be specified as part of the command using attribute-based command field 12c and data field 12d (FIG. 2). Processors 112A and 112B may generate PWM signals to operate actuators 116A and 116B at specified torques and rotation times.

3. Operation of Power Assist Suit 30 Next, the processing when the power assist suit 30 starts operating will be described.

In this specification and drawings, values written in data structures are represented by binary numbers or hexadecimal numbers. These are merely different in form, and are merely selected in relation to the space of the drawings. Those skilled in the art will understand that these entities are the same. In addition, "0x" is attached to the hexadecimal value.

FIG. 7 shows an example of a data frame 2a that the control unit 150 sends to all actuator units. Data frame 2a corresponds to data frame 1a in FIG. 1A, and its data structure conforms to the RS-485 standard. A description of the example corresponding to the data frame 1b used in wireless communication shown in FIG. 1B is omitted, but a person skilled in the art can understand it based on the example of FIG.

The control circuit 154 of the control unit 150 sets the identifier "0x02" of the control unit 150 as the source device ID10, and sets the address (0xFF) for all identifiers as the destination device ID11.

Further, the control circuit 154 sets "0x06" indicating a multicast command in the action system command field 12b of the common data structure 12, and sets "0x00, 0x01" indicating a control mode in the attribute system command field 12c. ”. Then, the control circuit 154 sets "0x01" indicating forward walking in the data field 12d. As an example, "0x00", "0x01", "0x02", "0x03", and "0x04" are associated with release, forward walking, backward walking, lifting, and unloading motions, respectively. Other data fields are not specifically relevant to this disclosure. Therefore, description of other data fields is omitted.

All the actuator units that received the data frame 2a continue processing the data frame 2a because "0xFF" is described in the destination device ID. Each actuator unit recognizes the operation mode of the power assist suit 30 by referring to the value written in the data field 12d.

Each actuator unit refers to the lookup table shown in Table 1 based on the recognized operation mode, and reads out the operation parameters necessary for the operation to be performed by itself in the designated operation mode. If there is no operation parameter corresponding to its own lookup table, it means that it does not need to operate in the specified operation mode.

Next, the operation of each actuator unit will be described. In the following description, an example of walking forward while the two left and right actuator units 106A and 106B provided at the hip joint shown in FIG. 5 communicate with each other will be given. During forward walking, actuator units such as both knees, both ankles, both shoulders, and both elbows can also operate. However, since it would be very complicated to describe them including them, only the two left and right actuator units 106A and 106B will be described. Based on the description of actuator units 106A and 106B, those skilled in the art will understand that the other actuator units will work similarly.

In the following description, it is assumed that the device IDs of the left actuator unit 106A and the right actuator unit 106B are "0x03" and "0x04", respectively.

FIG. 8 shows the relationship between the rotation angle of each actuator provided in the left and right actuator units 106A and 106B and time during forward walking. A thick solid line relates to the left actuator unit 106A, and a thin solid line relates to the right actuator unit 106B. The horizontal axis is time and the vertical axis is angle. The direction in which the thigh is lifted forward is defined as a positive angle, and the direction in which the thigh is pushed backward is defined as a negative angle.

Forward walking can be achieved by lifting the right and left thighs of the power assist suit 30 forward or sending them backward at the timings and angles shown.

FIG. 9 shows coordinated operations during assist operations realized by mutual communication between the actuator units 106A and 106B. As in FIG. 8, the thick solid line relates to the left actuator unit 106A, and the thin solid line relates to the right actuator unit 106B.

Thick dashed lines Assist-F1 and F2 shown in FIG. 9 indicate that the “thigh lifting assist torque” is applied. The thigh lifting assist torque is an assist torque applied in a direction to lift the thigh forward. The thigh lifting assist torque is continuously applied until the rotation angle of the actuator reaches approximately 40 degrees. When the rotation angle of the actuator reaches approximately 40 degrees, the actuator unit stops generating thigh lifting assist torque. As a result, the thigh is lowered by gravity or human power, and the rotation angle of the actuator returns to the 0 degree direction.

On the other hand, the thick dashed line Assist-B indicates that the "delivery assist torque" is applied. The feed-out assist torque is an assist torque applied in a direction to feed out the thigh rearward. The delivery assist torque is continuously applied until the rotation angle of the actuator reaches about -40 degrees. When the rotation angle of the actuator reaches approximately -40 degrees, the actuator unit stops generating the feed-out assist torque. As a result, the thigh is lowered by gravity or human power, and the rotation angle of the actuator returns to the 0 degree direction.

In the present embodiment, no assist torque is generated in a direction to decrease the rotation angle from +40 degrees and an assist torque in a direction to increase the rotation angle from -40 degrees. However, one or both of the assist torques may be generated.

Mutual communication between the actuator units 106A and 106B is performed at timings T1 to T6 when the rotation angle of each actuator reaches a threshold value. FIG. 9 shows the threshold LA applied to the left actuator unit _106A and the threshold _RA applied to the right actuator unit 106B. In this embodiment, the threshold L _A is set to -23 degrees, and the threshold R _A is set to -30 degrees. The reason why the values of the thresholds _{LA and RA are} different is for the convenience of illustration. The values of thresholds L _A and R _A may be the same.

First, attention is paid to time T1. Time T1 indicates the timing when the rotation angle of the actuator of the right actuator unit 106B continues to decrease and reaches the threshold _RA . The right actuator unit 106B sends a notification to the left actuator unit 106A. Notifications are sent to inform the left actuator unit 106A when the left actuator unit 106A should take action.

FIG. 10 shows an example of a data frame 2a transmitted from the right actuator unit 106B to the left actuator unit 106A. In the data frame 2a, the transmission source device ID 10 describes "0x04" indicating the right actuator unit 106B, and the transmission destination device ID 11 describes "0x03" indicating the left actuator unit 106A. Also, in the action system command field 12b of the common data structure 12, "0x0E" indicating the start of action is described. That is, each actuator unit that receives the data frame 2a in which "0x0E" is described in the operation system command field 12b starts driving the actuator at that timing. By transmitting the data frame 2a shown in FIG. 10, the start of operation can be notified to the destination actuator unit.

In response to receiving the notification (data frame 2a) from the right actuator unit 106B, the left actuator unit 106A drives the actuator to start applying assist torque. It can be understood from the thick dashed line Assist-F1 that the assist torque is generated from time T1.

Next, attention is paid to time T2. Time T2 indicates the timing when the rotation angle of the actuator of the left actuator unit 106A continues to decrease and reaches the threshold _LA . As in the previous example, the left actuator unit 106A sends a notification to the right actuator unit 106B. This notification is sent to inform the right actuator unit 106B when the right actuator unit 106B should take action. The left actuator unit 106A may generate and transmit the data frame 2a in which the source device ID and the destination device ID in FIG. 10 are interchanged.

In response to receiving the notification from the left actuator unit 106A, the right actuator unit 106B drives the actuator to start applying assist torque. It can be understood from the thick dashed line Assist-F2 that the assist torque is generated from time T2.

By repeating the above process, a notification is sent from the right actuator unit 106B to the left actuator unit 106A, or vice versa, from the left actuator unit 106A to the right actuator unit 106B. The actuator unit that receives each notification applies assist torque.

After first transmitting the data frame 2a shown in FIG. 7 to all the actuator units, the control unit 150 does not control the operation of each actuator unit. Therefore, the computational resources of the control circuit 154 of the control unit 150 can be allocated to other processes.

FIG. 11 is a timing chart showing the relationship between the operation timings of the control unit 150, the left actuator unit 106A, and the right actuator unit 106B. For reference, times T1 and T2 are shown.

Next, the processing of the control unit 150, the right actuator unit 106B and the left actuator unit 106A will be described with reference to FIGS. 12 to 14. FIG.

FIG. 12 is a flow chart showing the procedure of processing executed by the control circuit 154 of the control unit 150. As shown in FIG.

In step S1, the control circuit 154 determines whether or not there is a trigger (condition) for generating assist torque. If the trigger exists, the process proceeds to step S2; otherwise, the process proceeds to step S4.

Various triggers are conceivable. For example, an instruction to start operation from the wearer of the power assist suit 30 is an example of a trigger. Further, when a torque sensor is provided on the waist of the power assist suit 30, the output from the torque sensor can be used to detect that the wearer is about to start walking as a trigger. When a sensor switch is provided on the arm or hand of the power assist suit 30, the output from the sensor switch can be used to detect the wearer's attempt to lift an object as a trigger. can. In the example above, it can also be detected that a trigger that was present is no longer present.

At step S2, the control circuit 154 determines whether or not the assist operation is currently being performed. If the assist is in progress, the processing of the control unit 150 ends. At this time, assist processing is continued by a plurality of actuator units. If the assist is not being performed, the process proceeds to step S3.

In step S3, the control circuit 154 generates a data frame 2a including an operation mode designation command (FIG. 7) to each actuator unit, and transmits the data frame 2a via the communication circuit 152. FIG.

Step S4 is determination processing when there is no trigger. At step S4, the control circuit 154 determines whether or not the assist operation is currently being performed. If the assist is not being performed, the processing of the control unit 150 ends. If the assist is being performed, the process proceeds to step S5.

In step S5, since there is no trigger, the control circuit 154 transmits a command to stop the assist operation. The stop command is stored, for example, in the data frame 2a and sent to each actuator unit.

FIG. 13 is a flow chart showing the procedure of processing executed by the processor 112B of the right actuator unit 106B.

In step S11, the processor 112B waits until there is an assist start command. The assist start command is equivalent to receiving an operation mode designation command from the control circuit 154 of the control unit 150 .

In step S12, the processor 112B determines whether or not to stop the assist. In the case of stopping, the process proceeds to step S13 to execute stop processing. If the assist is not to be stopped, the process proceeds to step S14.

At step S14, processor 112B reads the rotation angle and direction of movement of actuator 116B. For example, the processor 112B can read the rotation angle and movement direction of the actuator 116B, for example, from outputs of a plurality of Hall elements (not shown) provided on the actuator 116B.

At step S15, the processor 112B refers to the angle-torque data (FIGS. 6A and 6B) to calculate the magnitude of the assist torque.

In step S16, the processor 112B changes the magnitude of the current assist torque according to the calculated assist torque.

In step S17, the processor 112B determines whether or not the application of the assist torque is in the direction of the negative angle. If so, the process proceeds to step S18; otherwise, the process proceeds to step S21.

At step S18, the processor 112B determines whether or not the command has been sent to the left actuator unit 106A. If it has been transmitted, the process proceeds to step S21, and if it has not been transmitted, the process proceeds to step S19.

In step S19, the processor 112B determines whether or not the rotation angle of the actuator 116B is _LA or less. If the rotation angle is less than or equal to _LA , the process proceeds to step S20; otherwise, the process proceeds to step S21.

In step S20, the processor 112B generates a data frame 2a including an assist start command (FIG. 10) and transmits it to the left actuator unit 106A via the communication circuit 110B.

In step S21, the processor 112B determines whether or not to end the application of the assist torque. For example, processor 112B determines whether the rotation angle of actuator 116B has reached ±40 degrees. If it is determined that it has reached, the process returns to step S11, and if it has not reached, the process returns to step S12. After that, the above processing is repeated again.

FIG. 14 is a flow chart showing the procedure of processing executed by the processor 112A of the left actuator unit 106A. The processes from steps S31 to S41 in FIG. 14 respectively correspond to the processes from steps S11 to S21 in FIG. Therefore, description of each process from step S31 to step S41 is omitted. In the description of FIG. 13, the processor 112B of the right actuator unit 106B should be read as the processor 112A of the left actuator unit 106A, and the command transmission destination should be read as the left actuator unit 106A. 13 and 14 are the thresholds used in step S19 of FIG. 13 and step S39 of FIG. 14, respectively. At step S39 in FIG. 14, the threshold _RA is employed.

According to the above processing, the control circuit 154 of the control unit 150 only needs to first send the operation mode designation command (FIG. 7) to all the actuator units. After that, even if the control circuit 154 does not control the operation of each actuator unit, the power assist suit 30 can be operated while each actuator unit communicates with each other. Since the operation of the power assist suit 30 as a whole is realized by communication between the actuator units, processing in the control circuit 154 is unnecessary. Higher processing speed can also be achieved without intervention of the control circuit 154 .

Furthermore, the computational resources of the control circuit 154 of the control unit 150 can be allocated to other processes. Specific examples of "other processing" are information processing for a man-machine interface, and actuator failure prediction processing by obtaining sensor data indicating actuator behavior. In the information processing for the man-machine interface, the intention of the wearer of the control unit 150 can be more accurately reflected in the operation of the actuator. In the actuator failure prediction process, the control circuit 154 acquires the statistics of the actuator operation status and the output signal of the sensor mounted on the actuator, and the actuator fails when it matches a failure pattern prepared in advance. can be determined to be highly probable. Alternatively, it is possible to perform a process of transmitting the acquired data to the cloud computer, and acquire the information of the failure of the actuator predicted by the cloud computer.

In the above description, Wi-Fi is used as an example of the wireless communication standard, but other wireless communication standards such as the Bluetooth (registered trademark) standard may be adopted.

Any of the general or specific aspects described above may be implemented by a system, method, integrated circuit, computer program, or recording medium. Alternatively, it may be implemented by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

The processing according to the present disclosure can be suitably used in equipment that drives actuator units using a communication network.

This application claims priority based on Japanese Patent Application No. 2017-251368 filed on December 27, 2017, and incorporates all the descriptions described in the Japanese application.

30 power assist suit 104A joint mechanism 106A actuator unit 110A communication circuit 111A buffer 112A processor (control circuit) 113A memory 114A drive circuit 116A joint actuator 104B joint mechanism 106B actuator unit 110B Communication circuit 111B Buffer 112B Processor (control circuit) 113B Memory 114B Drive circuit 116B Joint actuator 150 Control unit 152 Communication circuit 154 Control circuit

Claims (14)

A control unit and a plurality of actuator units respectively provided at a plurality of joints are provided, and the control unit and each actuator unit and the plurality of actuator units are connected to each other by a communication network so as to be communicable. A power assist suit,
the control unit has a communication circuit and a control circuit;
the plurality of actuator units includes a first actuator unit and a second actuator unit;
each of the first actuator unit and the second actuator unit,
a processing circuit that generates a control signal;
an actuator;
a drive circuit that drives the actuator according to the control signal;
a storage device storing a plurality of operation parameters for operating the actuator for each operation mode;
a communication circuit for transmitting and receiving data frames between the control unit and other actuator units,
said control unit sending a command specifying a predetermined operating mode to said first actuator unit and said second actuator unit;
In the first actuator unit that received the command ,
The processing circuit is
reading the plurality of operating parameters corresponding to the specified predetermined operating mode from the storage device;
receiving an assist command from the second actuator unit;
generating a first control signal, which is the control signal, using the plurality of operating parameters in response to receiving the assist command;
causing the drive circuit to drive the actuator according to the first control signal;
transmitting an assist command to the second actuator unit at a first timing;
In the second actuator unit that received the command ,
The processing circuit is
reading the plurality of operating parameters corresponding to the specified predetermined operating mode from the storage device;
receiving an assist command from the first actuator unit;
generating a second control signal, which is the control signal, using the plurality of operating parameters in response to receiving the assist command;
causing the drive circuit to drive the actuator according to the second control signal;
transmitting an assist command to the first actuator unit at a second timing;
The storage device stores, as one of the plurality of operating parameters, angle-torque data that associates an angle of the actuator with a magnitude of assist torque,
The power assist suit , wherein the processing circuit acquires angle data indicating a rotation angle of the actuator, and determines the magnitude of the assist torque by referring to the angle-torque data based on the angle data . 2. The power assist suit according to claim 1 , wherein the angle-torque data indicates that the assist torque of the actuator is zero when the rotation angle of the actuator is within a predetermined angle range including 0 degrees. the first timing is determined according to a relationship between a rotation angle of the actuator of the first actuator unit and a first threshold;
3. The power assist suit according to claim 1, wherein said second timing is determined according to the relationship between the rotation angle of the actuator of said second actuator unit and a second threshold value. A control unit and a plurality of actuator units respectively provided at a plurality of joints are provided, and the control unit and each actuator unit and the plurality of actuator units are connected to each other by a communication network so as to be communicable. A power assist suit,
the control unit has a communication circuit and a control circuit;
the plurality of actuator units includes a first actuator unit and a second actuator unit;
each of the first actuator unit and the second actuator unit,
a processing circuit that generates a control signal;
an actuator;
a drive circuit that drives the actuator according to the control signal;
a storage device storing a plurality of operation parameters for operating the actuator for each operation mode;
a communication circuit for transmitting and receiving data frames between the control unit and other actuator units;
and
said control unit sending a command specifying a predetermined operating mode to said first actuator unit and said second actuator unit;
In the first actuator unit that received the command,
The processing circuit is
reading the plurality of operating parameters corresponding to the specified predetermined operating mode from the storage device;
receiving an assist command from the second actuator unit;
generating a first control signal, which is the control signal, using the plurality of operating parameters in response to receiving the assist command;
causing the drive circuit to drive the actuator according to the first control signal;
transmitting an assist command to the second actuator unit at a first timing;
In the second actuator unit that received the command,
The processing circuit is
reading the plurality of operating parameters corresponding to the specified predetermined operating mode from the storage device;
receiving an assist command from the first actuator unit;
generating a second control signal, which is the control signal, using the plurality of operating parameters in response to receiving the assist command;
causing the drive circuit to drive the actuator according to the second control signal;
transmitting an assist command to the first actuator unit at a second timing;
the first timing is determined according to a relationship between a rotation angle of the actuator of the first actuator unit and a first threshold;
The power assist suit, wherein the second timing is determined according to a relationship between a rotation angle of the actuator of the second actuator unit and a second threshold. When each of the first and second actuator units is provided at a hip joint that operates the left and right thighs of the power assist suit,
the first timing is the timing at which the rotation angle of the actuator of the first actuator unit reaches the first threshold value from 0 degrees;
5. The power assist suit according to claim 3 , wherein the second timing is the timing when the rotation angle of the actuator of the second actuator unit reaches the second threshold value from 0 degrees. The first timing indicates the timing at which the second actuator unit lifts the right thigh,
6. The power assist suit according to claim 5, wherein said second timing indicates timing at which said first actuator unit lifts the left thigh. The first actuator unit causes the actuator to generate a first thigh lift assist torque for lifting the left thigh forward, and when the rotation angle of the actuator reaches a predetermined angle, the first thigh lifts the first thigh. After stopping the generation of the lifting assist torque and lowering the left thigh, causing the actuator to generate a first send-out assist torque for sending the left thigh rearward,
7. The power assist suit according to claim 6, detecting that the rotation angle of said actuator reaches said first threshold value while generating said first delivery assist torque. The second actuator unit causes the actuator to generate a second thigh lifting assist torque that lifts the right thigh forward, and when the rotation angle of the actuator reaches the predetermined angle, the second thigh lifts the second thigh. After stopping the generation of the thigh lifting assist torque and lowering the right thigh, causing the actuator to generate a second send-out assist torque for sending the right thigh backward,
8. The power assist suit according to claim 6 or 7, wherein it detects that the rotation angle of said actuator reaches said second threshold value while generating said second delivery assist torque. the control unit has a host identifier that uniquely identifies itself within the communication network;
The control circuit of the control unit includes the host identifier indicating itself as a transmission source, a predetermined identifier indicating all actuator units as a transmission destination, and operation mode data specifying the predetermined operation mode. 9. The power assist suit according to any one of claims 1 to 8, wherein the data frame storing the is transmitted to the communication network. the first actuator unit has a first identifier that uniquely identifies itself within the communication network;
the second actuator unit has a second identifier that uniquely identifies itself within the communication network;
At the first timing, the first actuator unit has the first identifier indicating itself as a transmission source, the second identifier indicating the second actuator unit as a transmission destination, and the operation start of the second actuator unit. 10. The power assist suit according to claim 9, wherein a data frame containing said assist command for notifying is sent to said communication network. the first actuator unit has a first identifier that uniquely identifies itself within the communication network;
the second actuator unit has a second identifier that uniquely identifies itself within the communication network;
At the second timing, the second actuator unit has the second identifier indicating itself as a transmission source, the first identifier indicating the first actuator unit as a transmission destination, and the operation start of the first actuator unit. 10. The power assist suit according to claim 9, wherein a data frame storing said assist command for notifying is sent to said communication network. 12. Any one of claims 9 to 11, wherein said host identifier, said first identifier and said second identifier are device identifiers assigned to each of said control unit, said first actuator unit and said second actuator unit. Power assist suit as described. 13. A power assist suit according to claim 12, wherein said device identifier is a MAC address. 13. A power assist suit according to claim 12, wherein said device identifier is an IP address.

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