WO2023195146A1

WO2023195146A1 - Robot device and ultrasound diagnostic system

Info

Publication number: WO2023195146A1
Application number: PCT/JP2022/017321
Authority: WO
Inventors: 伸哉近藤; 直史吉田
Original assignee: 株式会社Fuji
Priority date: 2022-04-08
Filing date: 2022-04-08
Publication date: 2023-10-12

Abstract

This robot device comprises: a robot body; a driving unit that drives the robot body; an external force detecting unit that detects an external force acting on the robot body; and a control unit that transitions to a safe state for controlling the driving unit so that the robot body performs an evacuation action in a prescribed direction when an external force acting on the robot body has been detected by the external force detecting unit.

Description

Robotic equipment and ultrasound diagnostic systems

This specification discloses a robotic device and an ultrasound diagnostic system.

Conventionally, this type of robot device has a collision detection unit that detects when the robot has collided with an object, and a deceleration unit that drives each motor of the robot to decelerate when it is detected that the robot has collided with an object. A first control unit that executes control; and a second control unit that executes dynamic braking for a predetermined period of time after the deceleration control is executed, stopping power supply to each motor and short-circuiting power input and output terminals in each motor. A device comprising the following has been proposed (see, for example, Patent Document 1). With this robot device, when the robot collides with an object, the robot can be quickly decelerated, and injuries to workers can be suppressed. Additionally, the operator can push the robot to move or move away from the robot while dynamic braking is being performed.

JP 2019-014008 Publication

However, in the above-mentioned robot device, when the robot collides with a worker, it is not possible to simply decelerate each motor of the robot or perform dynamic braking, and the force (pushing force) applied from the robot to the worker remains. However, there may be cases where worker safety cannot be sufficiently ensured.

The main purpose of the present disclosure is to provide a robot device or an ultrasound diagnostic system equipped with a robot device that can further improve safety against collisions between a robot and an object.

The present disclosure has taken the following measures to achieve the above-mentioned main objective.

The robot device of the present disclosure includes:
The robot body,
a drive unit that drives the robot body;
an external force detection unit that detects an external force acting on the robot body;
a control unit that controls the drive unit to move to a safe state so that the robot body moves in a predetermined direction when an external force acting on the robot body is detected by the external force detection unit;
The main point is to have the following.

The robot device of the present disclosure controls the drive unit so that the robot body moves in a predetermined direction when an external force acting on the robot body due to contact with an object is detected. As a result, when the robot body collides with an object, the pushing force of the robot body can be alleviated, and the safety of workers and the like can be further improved.

Since the ultrasound diagnostic system of the present disclosure includes an ultrasound probe and the robot device of the present disclosure that holds the ultrasound probe in its hand, it can achieve the same effects as the robot device of the present disclosure.

1 is an external perspective view of an ultrasonic diagnostic system including a robot device of this embodiment. FIG. 2 is a side view of the robot device. FIG. 2 is a block diagram showing an electrical connection relationship between a robot device and an ultrasonic diagnostic device. FIG. 3 is an explanatory diagram showing a movement trajectory of an ultrasound probe. 3 is a flowchart illustrating an example of collision determination processing. It is an explanatory diagram explaining a restricted area. It is a flowchart which shows an example of safety processing. FIG. 7 is an explanatory diagram showing compensation torques of the elevating axis J1 and each of the joint axes J2 to J7, which are set respectively in a normal state and a safe state.

Next, embodiments for carrying out the present disclosure will be described with reference to the drawings.

FIG. 1 is an external perspective view of an ultrasound diagnostic system 10 including a robot device 20 of this embodiment. FIG. 2 is a side view of the robot device 20. FIG. 3 is a block diagram showing the electrical connection relationship between the robot device 20 and the ultrasound diagnostic device 100. In addition, in FIG. 1, the left-right direction is the X-axis direction, the front-back direction is the Y-axis direction, and the up-down direction is the Z-axis direction.

The ultrasonic diagnostic system 10 of this embodiment holds an ultrasonic probe 101 at the tip of a robot arm 21, and operates the robot device 20 so that the ultrasonic probe 101 is pressed against the patient's body surface. Obtain an echo image. This ultrasonic diagnostic system 10 is used for catheter treatment, for example. The operator (operator) who operates the guide wire of the catheter presses the ultrasound probe 101 against the surface of the patient's thigh and recognizes the positional relationship between the tip of the guide wire and the blood vessel from the obtained ultrasound echo image. However, by advancing the guidewire, it is possible to accurately pass the guidewire through the center of the occluded or stenosed region of the blood vessel.

The ultrasound diagnostic system 10 of this embodiment includes a robot device 20, a console device 90, and an ultrasound diagnostic device 100, as shown in FIGS. 1 to 3.

As shown in FIG. 1, the ultrasound diagnostic device 100 includes an ultrasound probe 101 and an ultrasound diagnostic device main body 110 connected to the ultrasound probe 101 via a cable 102. As shown in FIG. 3, the ultrasound diagnostic device main body 110 includes an ultrasound diagnostic control unit 111 that controls the entire device, and an image processing unit that processes received signals from the ultrasound probe 101 to generate ultrasound echo images. 112, an image display section 113 that displays an ultrasound echo image, and various operation switches (not shown).

The console device 90 is provided separately from the robot device 20 and is used to instruct various operations of the robot device 20 and display various information including the status of the robot device 20. The console device 90 includes a console control section 91 that controls the entire device, an operation panel 92 that displays various information and can be touch-operated by an operator, a speaker 93, and a communication section 94 that communicates with the robot device 20. An emergency stop switch 95 is provided. The emergency stop switch 95 is a switch for stopping the operation of the robot device 20 in an emergency. Further, the console device 90 is connected to a foot pedal 96 and a joint controller 97 via a cable. The foot pedal 96 and the joint controller 97 are operating members that can give various instructions.

As shown in FIGS. 1 to 3, the robot device 20 includes a base 25, a robot arm 21 installed on the base 25, and a height adjustment mechanism 45 that adjusts the height of the robot arm 21 by manual operation. and a robot control device 80 (see FIG. 3) that controls the robot arm 21.

Casters 26 with stoppers are attached to the four corners of the back surface of the base 25, as shown in FIGS. 1 and 2. The robot device 20 can be freely moved by casters 26. Furthermore, locking portions 28 are provided at multiple locations (for example, three locations) on the back surface of the base 25 to protrude vertically downward by pressing down on the lever 27 to lock (fix) the robot device 20 immovably. .

The robot arm 21, as shown in FIG. has.

The base end of the first arm 22 is connected to the base 24 via a first joint shaft 31 (hereinafter sometimes referred to as "joint shaft J2") that extends in the vertical direction (Z-axis direction). . The first arm drive device 35 includes a motor 35a, an encoder 35b, and an amplifier 35c. The rotating shaft of the motor 35a is connected to the first joint shaft 31 via a reduction gear (not shown). The first arm driving device 35 rotates (swivels) the first arm 22 along a horizontal plane (XY plane) using the first joint axis 31 as a fulcrum by rotationally driving the first joint axis 31 with a motor 35a. . The encoder 35b is attached to the rotating shaft of the motor 35a, and is configured as a rotary encoder that detects the amount of rotational displacement of the motor 35a. The amplifier 35c is a drive unit for driving the motor 35a by switching a switching element.

The base end of the second arm 23 is connected to the distal end of the first arm 22 via a second joint shaft 32 (hereinafter sometimes referred to as "joint shaft J3") that extends in the vertical direction. . The second arm drive device 36 includes a motor 36a, an encoder 36b, and an amplifier 36c. The rotating shaft of the motor 36a is connected to the second joint shaft 32 via a speed reducer (not shown). The second arm driving device 36 rotates (swivels) the second arm 23 along a horizontal plane using the second joint shaft 32 as a fulcrum by rotationally driving the second joint shaft 32 with a motor 36a. The encoder 36b is attached to the rotating shaft of the motor 36a, and is configured as a rotary encoder that detects the amount of rotational displacement of the motor 36a. The amplifier 36c is a drive section for driving the motor 35a by switching a switching element.

The base 24 is provided so as to be movable up and down relative to the base 25 by a lifting device 40 installed on the base 25. As shown in FIGS. 1 and 2, the elevating device 40 includes a first slider 41 fixed to the base 24, a first guide member 42 that extends in the vertical direction and guides the movement of the first slider 41, and A first ball screw shaft 43 (hereinafter sometimes referred to as "elevating shaft J1") that extends in the direction and is screwed with a ball screw nut (not shown) fixed to the first slider 41; The motor 44a includes a motor 44a that rotationally drives a ball screw shaft 43, an encoder 44b (see FIG. 3), and an amplifier 44c that drives the motor 44a. The lifting device 40 moves the base 24 fixed to the first slider 41 up and down along the first guide member 42 by rotationally driving the first ball screw shaft 43 by the motor 44a. Therefore, the robot arm 21 moves up and down along the lifting axis J1. The encoder 44b is configured as a linear encoder that detects the vertical position (elevating position) of the first slider 41 (base 24).

As shown in FIG. 2, the height adjustment mechanism 45 includes a second slider 46 fixed to the first guide member 42 of the lifting device 40, and a second slider 46 fixed to the base 25 and extending in the vertical direction. A second guide member 47 that guides the movement of the second slider 46 and a second ball screw shaft 48 (elevating shaft) that extends in the vertical direction and is screwed with a ball screw nut (not shown) fixed to the second slider ) and an operation handle 49 connected to the second ball screw shaft 48 via a power transmission mechanism (bevel gear). The height adjustment mechanism 45 rotates the second ball screw shaft 48 by manually operating the operating handle 49, thereby moving the first guide member 42 of the lifting device 40 fixed to the second slider 46 to the second guide member 47. Move up and down along. The base end of the robot arm 21 is fixed to the base 24, and the base 24 is supported by the first guide member 42, so by moving the first guide member 42 up and down by the height adjustment mechanism 45, The height of the robot arm 21 can be adjusted. Thereby, for example, the height of the robot arm 21 can be adjusted according to the height of the bed on which the subject (patient) for ultrasound diagnosis lies.

As shown in FIGS. 1 and 2, the three-axis rotating mechanism 50 rotates the second arm 23 via a posture maintaining shaft 33 (hereinafter sometimes referred to as "joint axis J4") that extends in the vertical direction. Connected to the tip. The three-axis rotating mechanism 50 includes a first rotating shaft 51 (hereinafter sometimes referred to as "joint axis J5"), a second rotating shaft 52 (hereinafter sometimes referred to as "joint axis J6"), and A third rotating shaft 53 (hereinafter sometimes referred to as "joint axis J7"), a first rotating device 55 that rotates the first rotating shaft 51, and a second rotating device 56 that rotates the second rotating shaft 52. , and a third rotation device 57 that rotates the third rotation shaft 53. The first rotating shaft 51 is supported in a position orthogonal to the position maintaining shaft 33. The second rotating shaft 52 is supported in a position perpendicular to the first rotating shaft 51 . The third rotating shaft 53 is supported in a position orthogonal to the second rotating shaft 52. The first rotating device 55 includes a motor 55a that rotationally drives the first rotating shaft 51, an encoder 55b that is attached to the rotating shaft of the motor 55a and detects the amount of rotational displacement of the motor 55a, and an amplifier 55c that drives the motor 55a. has. The second rotating device 56 includes a motor 56a that rotationally drives the second rotating shaft 52, an encoder 56b that is attached to the rotating shaft of the motor 56a and detects the amount of rotational displacement of the motor 56a, and an amplifier 56c that drives the motor 56a. has. The third rotating device 57 includes a motor 57a that rotationally drives the third rotating shaft 53, an encoder 57b that is attached to the rotating shaft of the motor 57a and detects the amount of rotational displacement of the motor 57a, and an amplifier 57c that drives the motor 56a. has. Further, the third rotating shaft 53 is provided with a holding section 60 for holding the ultrasound probe 101.

The holding unit 60 holds the ultrasound probe 101 so as to be coaxial with the third rotating shaft 53. In this embodiment, the holding part 60 has a teaching mode, which will be described later, in which a worker manually operates the ultrasonic probe 101 while holding the ultrasonic probe 101 at the tip (holding part 60) of the robot arm 21. A switch 62 is provided to permit manual operation. This may be used as a direct teaching enable switch 62 to add a function to stop the robot arm 21 in an emergency.

The robot device 20 of the present embodiment can perform translational motion in three directions, that is, the X-axis direction, the Y-axis direction, and the Z-axis direction, by the first arm drive device 35, the second arm drive device 36, and the lifting device 40, and three rotational axes. In combination with the rotation movement of the mechanism 50 in three directions around the X axis (pitching), around the Y axis (rolling), and around the Z axis (yawing), the ultrasound probe 101 can be moved to any position in any posture within the movable area. can be moved to.

The posture holding device 37 maintains the posture of the rotating three-axis mechanism 50 (orientation of the first rotating shaft 51) in a constant direction regardless of the postures of the first arm 22 and the second arm 23. The posture holding device 37 includes a motor 37a, an encoder 37b, and an amplifier 37c. The rotating shaft of the motor 37a is connected to the posture maintaining shaft 33 via a reduction gear (not shown). The posture maintaining device 37 maintains the posture based on the rotation angle of the first joint shaft 31 and the rotation angle of the second joint shaft 32 so that the axial direction of the first rotation shaft 51 is always in the left-right direction (X-axis direction). A target rotation angle of the holding shaft 33 is set, and the motor 37a is drive-controlled so that the posture holding shaft 33 reaches the target rotation angle. This makes it possible to independently control translational motion in three directions and rotational motion in three directions, thereby facilitating control.

The force sensor 61 is attached to the tip of the robot arm 21, and detects force components acting in the directions of the X, Y, and Z axes and torque components acting around each axis as external forces acting on the robot arm 21. Detect.

As shown in FIG. 3, the robot control device 80 includes a robot control section 81, a monitoring section 82, an IO section 83, a communication section 84, and a storage section 85. The robot control unit 81 is configured as a processor including a CPU, ROM, RAM, peripheral circuits, and the like. The monitoring unit 82 is configured as a one-chip microcomputer including a CPU, ROM, RAM, peripheral circuits, and the like. Furthermore, the monitoring section 82 may be duplicated. The robot control unit 81 performs various processes related to controlling the robot arm 21 (motors 35a to 37a, 44a, 55a to 57a). The monitoring unit 82 monitors the status of each unit such as the IO unit 83, the communication unit 84, the amplifiers 35c to 37c, 44c, 55c to 57c, and the sensor unit including the encoders 35b to 37b, 44b, 55b to 57b, etc. The IO section 83 is an I/O port, and inputs a detection signal from the direct teaching enable switch 62 and inputs/outputs a signal from an external device. The communication unit 84 communicates with the robot control device 80 and the console device 90 by wire or wirelessly, and exchanges various control signals and data with each other.

The amplifiers 35c to 37c, 44c, and 55c to 57c each include a motor control section 71, a drive power supply section 72, and an IO section 73. The motor control unit 71 has switching elements, and controls each motor 35a to 37a, 44a, 55a to 57a by controlling the switching elements based on feedback signals from encoders 35b to 37b, 44b, 55b to 57b, etc. control. The drive power supply section 72 supplies the power necessary to drive the motors 35a to 37a, 44a, and 55a to 57a. The IO section 83 is an I/O port, and receives position signals from the encoders 35b to 37b, 44b, and 55b to 57b, and current signals from current sensors that detect the current flowing through each motor 35a to 37a, 44a, and 55a to 57a. , various signals such as command signals (control signals) are input from the robot control unit 81 to the respective motors 35a to 37a, 44a, and 55a to 57a.

Next, the operation of the robot device 20 included in the ultrasonic diagnostic system 10 configured in this way will be described. The robot device 20 of this embodiment has a direct teaching mode and an automatic operation mode as operating modes.

In the direct teaching mode, the position and orientation of the ultrasound probe 101 are registered at multiple arbitrary points while the operator grasps the tip (holding part 60) of the robot arm 21 that holds the ultrasound probe 101 and manually operates it. This is a possible mode. In the direct teaching mode, the robot control unit 81 (CPU) controls the vertical position Z1 of the vertical axis J1 and the vertical position of the joint axis J2 to J7 from each encoder 35b to 37b, 44b, 55b to 57b based on registration instructions from the operator. Obtain rotation angles θ2 to θ7. Next, the robot control unit 81 determines the position and posture of the hand of the robot arm 21 using forward kinematics, that is, the ultrasonic The position and orientation of the probe 101 are calculated. Then, the robot control unit 81 associates the acquired elevation position Z1 and rotation angles θ2 to θ7 with the calculated position and orientation of the ultrasound probe 101 and stores them in the storage unit 85 as registration points. Note that the operator's registration instruction can be given by, for example, pressing the foot pedal 96, operating the operation panel 92, or using voice recognition.

Here, a movable area is defined for the robot device 20. In the direct teaching mode, when the tip of the robot arm 21 (ultrasonic probe 101) approaches the boundary of the movable area, each motor 35a is moved so that a load (resistance) is applied in the opposite direction to the direction in which the robot arm 21 is operated by the operator. ~37a, 44a, 55a~57a. Thereby, it is possible to prevent the tip of the robot arm 21 from being operated beyond the movable area. Note that the operating direction of the robot arm 21 can be determined based on detection signals from the force sensor 61 and detection signals from the encoders 35b to 37b, 44b, and 55b to 57b.

The automatic operation mode is a mode in which the robot device 20 automatically moves the ultrasound probe 101 so as to pass through a plurality of points registered in the direct teaching mode in a predetermined order. In the automatic operation mode, when the operator instructs the robot controller 81 to start diagnosis, the robot controller 81 moves the ultrasound probe 101 to the first point among a plurality of points registered in advance. The movement of the ultrasonic probe 101 is performed by adjusting the lifting position of the lifting axis J1 and the rotation angle of the joint axes J2 to J7 of the robot arm 21 corresponding to the point to be moved (the position and posture of the hand of the robot arm 21) to the target lifting position Z1tag and the rotation angle of the joint axes J2 to J7. The target vertical position corresponding to the vertical position Z1 of the vertical axis J1 and the rotation angle θ2 to θ7 of the joint axes J2 to J7, which are set to the target rotation angles θ2tag to θ7tag and detected by each encoder 35b to 37b, 44b, 55b to 57b. This is done by controlling each of the motors 35a to 37a, 44a, and 55a to 57a to match Z1tag and target rotation angles θ2tag to θ7tag. The robot control unit 81 moves the ultrasonic probe 101 to the next point when the operator performs a forward operation. On the other hand, when the operator performs a return operation, the robot control unit 81 moves the ultrasound probe 101 to the previous point. Note that the forward operation and return operation can be performed by, for example, depressing the foot pedal 96, operating the operation panel 92, or operating by voice recognition.

In the automatic operation mode, the points (trajectory of movement) registered in the direct teaching mode are displayed in three dimensions on the operation panel 92 of the console device 90, as shown in FIG. When moving the ultrasonic probe 101 to the robot device 20, the operator can confirm in advance the destination of the ultrasonic probe 101 using the operation panel 92.

When applying ultrasonic diagnosis to catheter treatment, if the operator teaches the scanning direction of the ultrasonic probe 101 to match the central axis direction (lengthwise direction) of the patient's blood vessel in advance, automatic operation mode can be activated. By executing this, the ultrasound probe 101 can be automatically moved in the direction of the central axis of the blood vessel simply by operating the foot pedal 96. This allows a single operator to advance the guide wire while operating the ultrasound probe 101 and confirming the position of the patient's blood vessels from ultrasound echo images.

As described above, since the robot device 20 of this embodiment is assumed to work in the same space as the worker, there is a possibility that it will collide with another object (the worker). Therefore, the robot device 20 of the present embodiment determines whether or not there is a collision between the robot arm 21 (including the ultrasonic probe 101) and another object, and if it is determined that there has been a collision with another object, the robot arm 21 is moved away from the object. We are planning to move to a safe state where we will evacuate the area.

FIG. 5 is a flowchart showing an example of a collision determination process executed by the robot control unit 81 of the robot control device 80. This process is repeatedly executed at predetermined time intervals (for example, every few milliseconds or tens of milliseconds).

When the collision determination process is executed, the robot control unit 81 first determines whether the current state of the robot device 20 is the normal state (S100). If the robot control unit 81 determines that the current state is not a normal state but a safe state, it ends the collision determination process. On the other hand, if the robot control unit 81 determines that the current state is the normal state, the robot control unit 81 determines the vertical position Z1 of the vertical axis J1 and the rotation angle θ2 of the joint axes J2 to J7 from each encoder 35b to 37b, 44b, 55b to 57b. θ7 is input (S110), and the vertical speed V1 is calculated based on the input vertical position Z1, and the angular velocities ω2 to ω7 are calculated based on the input rotation angles θ2 to θ7 (S120). Then, the robot control unit 81 determines whether the vertical position Z1 is larger than the threshold Z1ref and whether the angular velocities ω2 to ω7 are larger than the corresponding thresholds ω2ref to ω7ref (S130). Here, the thresholds Z1ref, ω2ref to ω7ref are thresholds for determining whether the displacement of the robot arm 21 is caused by a collision with another object, and usually the vertical axis when operating the robot arm 21 is The speed is set to be slightly higher than the upper limit of the speed range of the vertical speed of J1 and the angular speed of joint axes J2 to J7. If the robot control unit 81 determines that the vertical speed V1 is equal to or lower than the threshold value V1ref and any of the angular velocities ω2 to ω7 are equal to or lower than the corresponding thresholds ω2ref to ω7ref, the robot control unit 81 determines that no collision with another object has occurred. The collision determination process ends.

On the other hand, if the robot control unit 81 determines that the vertical speed V1 is greater than the threshold value V1ref, or if it determines that any of the angular velocities ω2 to ω7 is greater than the corresponding threshold values ω2ref to ω7ref, it determines that the robot has collided with another object. (S140). Next, the robot control unit 81 uses forward kinematics to determine the hand position P of the robot arm 21 (ultrasonic probe 101 position) is calculated (S150), and the restricted area is updated based on the calculated hand position P (S160). Then, the robot control unit 81 shifts to a safe state (S170) and ends the collision determination process.

The restricted area is an area in the movable area where the movement of the robot arm 21 is restricted. When performing ultrasonic diagnosis by pressing the ultrasound probe 101 against the surface of a patient's thigh, a certain part of the thigh is a restricted area. In this embodiment, the restriction area is an initial area, which is the assumed maximum radius of the thigh (assumed maximum It is set in a circular (fan-shaped) area surrounded by the thigh radius). Then, when it is determined that the robot arm 21 has collided with another object (patient), the restricted area is defined as the distance between the hand position P (position of the ultrasound probe 101) and the predetermined position O at the time of the collision with a radius ( The area is updated (changed) to a circular (fan-shaped) area with the collision position radius). Note that the shape of the restricted area is not limited to a circular (fan-shaped) shape in a cross-sectional view of the thigh, but may be an ellipse, an egg shape, or the like. Further, the restricted area may be set to have a cylindrical shape or a tapered shape in the depth direction in FIG. 6 . The operation of the robot device 20 when the tip of the robot arm 21 (ultrasonic probe 101) enters the restricted area in the safe state will be described later.

Next, the operation of the robot device 20 in a safe state will be described. FIG. 7 is a flowchart showing an example of safety processing executed by the robot control unit 81. This process is repeatedly executed at predetermined time intervals (for example, every several milliseconds or tens of milliseconds) from the transition to the safe state until the end of the safe state.

When the safety process is executed, the robot control unit 81 first inputs the elevation position Z1 of the elevation axis J1 and the rotation angles θ2 to θ7 of the joint axes J2 to J7 from the encoders 35b to 37b, 44b, and 55b to 57b ( S200), the hand position P, the retraction distance L, and the retraction speed V are calculated (S210). The calculation of the hand position P has been described above. In addition, the evacuation distance L is the cumulative amount of movement of the hand position P after transitioning to the safe state, and can be calculated by integrating the distance between the hand position P calculated this time and the hand position calculated last time. . The retreat speed V can be calculated by dividing the distance between the currently calculated hand position P and the previously calculated hand position by the safety process execution time interval.

Next, the robot control unit 81 determines whether the hand position P is within the restricted area (S220), whether the evacuation distance L exceeds the threshold Lref (S230), and whether the evacuation speed V exceeds the threshold Vref. (S240) and whether a predetermined time has elapsed since transition to the safe state (S250). The robot control unit 81 determines that the hand position P is not within the restricted area, the evacuation distance L is less than or equal to the threshold value Lref, the evacuation speed V is less than or equal to the threshold value Vref, and a predetermined period of time has elapsed since the transition to the safe state. If it is determined that it is not, the lifting speed V1 is calculated based on the lifting position Z1 input in S200, and the angular velocities ω2 to ω7 are calculated based on the rotation angles θ2 to θ7 input in S200 (S260). Next, the robot control unit 81 sets a compensation torque Tc1 for the vertical axis J1 based on the calculated vertical speed V1, and also sets a compensation torque Tc2 to Tc7 for the joint axes J2 to J7 based on the calculated angular velocities ω2 to ω7. (S270). Next, the robot control unit 81 sets the torque that is the original torque that should be output to the lifting axis Z1 and the compensation torque Tc1 added to it as the torque command for the lifting axis Z1, and also sets the torque that is the original torque that should be output to the lifting axis Z1 to the original torque that should be output to each of the joint axes J2 to J7. The torque obtained by adding each compensation torque Tc2 to Tc7 to the torque is set as the torque command for the joint axes J2 to J7 (S280). Then, the robot control unit 81 controls each motor 35a to 37a, 44a, and 55a to 57a so that a torque corresponding to the set torque command is output (S290), and ends the safety process.

In the safe state, when the robot arm 21 moves along the lifting axis Z1 due to a reaction force due to a collision with another object, a torque corresponding to (proportional to) the lifting speed V1 is output in the moving direction. Further, when the robot arm 21 rotates around the joint axes J2 to J7 due to a reaction force due to a collision with another object, a torque corresponding to (proportional to) the angular velocities ω2 to ω7 is output in the direction of rotation. FIG. 8 is an explanatory diagram showing compensation torques of the elevating axis J1 and each of the joint axes J2 to J7, which are set respectively in the normal state and the safe state. In the safe state, the compensation torques Tc1 to Tc7 include a compensation torque for static friction (static friction compensation) and a compensation torque for viscous friction (viscous friction compensation). The above-mentioned torque corresponding to the vertical speed V1 and the angular velocities ω2 to ω7 is added to the viscous friction compensation term. Note that the compensation torques of the lifting axis J1 and the joint axes J5 to J7 include a compensation torque (gravity compensation) in a direction that cancels out the load torque due to the body's own weight in both the normal state and the safe state. Since the joint axes J2 to J4 extend vertically in the axial direction, gravity compensation is not necessary.

Through such safety processing, the robot device 20 can evacuate the robot arm 21 that collided with the object (worker) in a direction away from the object. As a result, the pressing force of the robot arm 21 can be quickly relaxed, and the safety of the worker can be sufficiently ensured. Further, the retracting operation of the robot arm 21 is executed by a torque corresponding to an external force acting on the robot arm 21. Therefore, if the external force is no longer applied to the robot arm 21, the torque corresponding to the external force will not be output. This allows the robot device 20 to retreat the robot arm 21 by the amount necessary to alleviate the pushing force, thereby suppressing the occurrence of secondary damage such as collision with another object during the retreat operation, for example. be able to.

The robot control unit 81 determines that the hand position P is within the restricted area in S220, determines that the retraction distance L exceeds the threshold value Lref in S230, or determines that the retraction speed V exceeds the threshold value Vref in S240. If it is determined that there is, or that a predetermined time has elapsed since the transition to the safe state in S250, the safe state is ended (S300) and the safety process is ended. Specifically, the robot control unit 81 controls each motor 35a to 37a, 44a, and 55a to 57a so that the retracting operation of the robot arm 21 is stopped. Thereby, it is possible to avoid an unexpected movement in the retracting operation of the robot arm 21, and to suppress the occurrence of secondary damage.

Here, the correspondence between the main elements of the embodiment and the main elements of the present disclosure described in the claims will be explained. That is, the robot arm 21 of this embodiment corresponds to the robot main body, the motors 35a to 37a, 44a, and 55a to 57a correspond to the drive section, and the encoders 35b to 37b, 44b, and 55b to 57b correspond to the external force detection section. , the robot control section 81 corresponds to the control section. The encoders 35b to 37b, 44b, and 55b to 57b also correspond to the position detection section. Further, the ultrasonic probe 101 corresponds to an ultrasonic probe.

It goes without saying that the present disclosure is not limited to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present disclosure.

For example, in the embodiment described above, the robot device 20 determines whether the vertical speed V1 of the vertical axis J1 and the angular velocities ω2 to ω7 of the joint axes J2 to J7 are larger than the corresponding thresholds Z1ref, ω2ref to ω7ref. The external force acting on the robot arm 21 due to a collision with another object is detected. However, the robot device 20 detects the external force acting on the robot arm 21 due to a collision with another object by detecting the torque acting on the lifting axis J1 and the joint axes J2 to J7 using a torque sensor. It's okay. In this case, the robot control unit 81 may set a compensation torque corresponding to (proportional to) the detected torque in the direction of the detected torque. Further, the robot device 20 may directly detect the external force acting on the robot arm 21 using the force sensor 61. In this case, as the external force acting on the robot arm 21, the force sensor 61 detects force components acting in the directions of the X, Y, and Z axes, and torque components acting around each axis. Therefore, the robot control unit 81 uses a conversion matrix to convert the force component and torque component detected by the force sensor 61 into the torque of the vertical axis J1 and each joint axis J2 to J7, and sets the compensation torque. good.

Further, in the embodiment described above, the robot control unit 81 sets the robot arm 21 in the direction of the external force acting on the robot arm 21 due to the collision with another object (the direction of the vertical speed V1 and the angular velocities ω2 to ω7) as the retraction direction. The motors 35a to 37a, 44a, and 55a to 57a are controlled so that the motor 21 is retracted. However, the robot control unit 81 sets the direction of the retracting motion of the robot arm 21 to be opposite to the direction of the motion of the robot arm 21 at the time of the collision (the vertical direction of the vertical axis J1, the rotational direction of the joint axes J2 to J7). You may.

Furthermore, in the embodiment described above, the robot device 20 is configured as a seven-axis articulated robot capable of translational movement in three directions and rotational movement in three directions. However, the number of axes may be any number. Further, the robot device 20 may be configured by a so-called vertically articulated robot, horizontally articulated robot, or the like.

As described above, the robot device of the present disclosure controls the drive unit so that the robot body moves in a predetermined direction when an external force acting on the robot body due to contact with an object is detected. As a result, when the robot body collides with an object, the pushing force of the robot body can be alleviated, and the safety of workers and the like can be further improved.

In such a robot device of the present disclosure, the control unit may control the drive unit so that, as the safe state, the larger the detected external force is, the larger the driving force is used to cause the robot main body to retreat. In this way, when the robot body collides with another object (worker), the pushing force of the robot body can be reduced by the necessary amount, and the safety of the worker etc. can be further improved.

Furthermore, in the robot device of the present disclosure, the control unit may control the drive unit so that the robot main body performs a retracting operation in the direction of the detected external force as the safe state. In this way, the retraction direction of the robot body can be appropriately determined through simple processing.

Furthermore, the robot device of the present disclosure includes a position detection unit that detects the position of the robot body, the robot body is a robot body of a medical robot used for diagnosis and treatment of patients, and the control unit includes: The robot controls the drive unit so that the robot body operates based on the assumed thigh position of the patient, and the robot body is detected by the position detection unit when an external force acting on the robot body is detected. The thigh position may be changed based on the position of the main body. In this way, when working on a patient's thigh, it is possible to appropriately grasp the position of the thigh, which varies from person to person.

Further, in the robot device of the present disclosure, the control unit may terminate the retreating operation when the robot main body enters a restricted area set within a movable area due to the retreating operation in the safe state. . In this way, it is possible to avoid unexpected operations during the evacuation operation and to suppress the occurrence of secondary damage. In this case, the controller includes a position detection unit that detects the position of the robot body, and the control unit controls the robot body detected by the position detection unit when an external force acting on the robot body is detected by the external force detection unit. A predetermined range with the position of the main body as a boundary may be set as the restricted area. In this way, the restriction area can be set appropriately.

Further, in the robot device of the present disclosure, the control unit may control, when a predetermined period of time has elapsed since the transition to the safe state, and when the amount of movement of the robot main body in the evacuation operation exceeds a predetermined amount in the safe state; Alternatively, the evacuation operation may be terminated when the moving speed of the robot main body during the evacuation operation exceeds a predetermined speed in the safe state. In this way, it is possible to avoid unexpected operations during the evacuation operation and to suppress the occurrence of secondary damage.

Further, in the robot device of the present disclosure, the robot main body has an arm, the drive section has a motor that drives a joint shaft of the arm, and the external force detection section is configured to detect an external force acting on the robot main body. detects the angular velocity of the joint shaft or the torque acting on the joint shaft, and the control unit, in the safe state, applies an additional torque corresponding to the detected angular velocity or torque to the detected angular velocity from the corresponding motor. Alternatively, the drive unit may be controlled so that the torque is output in the direction of torque. In this way, the evacuation operation can be performed appropriately.

Alternatively, in the robot device of the present disclosure, the robot main body includes an arm, the drive unit includes a motor that drives a joint shaft of the arm, and the external force detection unit detects a force provided on the arm. the control unit controls the drive unit so that, in the safe state, an additional torque corresponding to the detected value of the force sensor is output from the corresponding motor in the direction of the detected external force. You may. In this way, the evacuation operation can be performed appropriately.

Note that the present disclosure is not limited to the form of a robot device, but can also be applied to an ultrasonic diagnostic system.

The present disclosure can be used in the manufacturing industry of robotic devices and ultrasonic diagnostic systems.

10 Ultrasonic diagnostic system, 20 Robot device, 21 Robot arm, 22 First arm, 23 Second arm, 24 Base, 25 Base, 26 Caster, 27 Lever, 28 Lock part, 31 First joint axis, 32 Second Joint axis, 33 Posture maintenance axis, 35 First arm drive device, 35a Motor, 35b Encoder, 35c Amplifier, 36 Second arm drive device, 36a Motor, 36b Encoder, 36c Amplifier, 37 Posture maintenance device, 37a Motor, 37b Encoder, 37c amplifier, 40 lifting device, 41 first slider, 42 first guide member, 43 first ball screw shaft, 44a motor, 44b encoder, 44c amplifier, 45 height adjustment mechanism, 46 second slider, 47 second Guide member, 48 second ball screw shaft, 49 operating handle, 50 rotating three-axis mechanism, 51 first rotating shaft, 52 second rotating shaft, 53 third rotating shaft, 55 first rotating device, 55a motor, 55b encoder, 55c amplifier, 56 second rotation device, 56a motor, 56b encoder, 56c amplifier, 57 third rotation device 57a motor 57b encoder, 57c amplifier, 60 holding section, 61 force sensor, 62 switch, 71 motor control section, 72 drive Power supply unit, 73 IO unit, 80 robot control device, 81 robot control unit, 82 monitoring unit, 83 IO unit, 84 communication unit, 85 storage unit, 90 console device, 91 console control unit, 92 operation panel, 93 speaker, 94 Communication section, 95 Emergency stop switch, 96 Foot pedal, 97 Joint controller, 100 Ultrasonic diagnostic device, 101 Ultrasonic probe, 102 Cable, 110 Ultrasonic diagnostic device main body, 111 Ultrasonic diagnostic control section, 112 Image processing section, 113 Image display section, J1 lifting axis, J2, J3, J4, J5, J6, J7 joint axes.

Claims

The robot body,
a drive unit that drives the robot body;
an external force detection unit that detects an external force acting on the robot body;
a control unit that controls the drive unit to move to a safe state so that the robot body moves in a predetermined direction when an external force acting on the robot body is detected by the external force detection unit;
A robot device equipped with.
The robot device according to claim 1,
The control unit controls the drive unit so that, as the safe state, the larger the detected external force is, the larger the driving force is used to cause the robot main body to perform a retracting operation.
robotic equipment.
The robot device according to claim 1 or 2,
The control unit controls the drive unit so that the robot main body retreats in the direction of the detected external force as the safe state.
robotic equipment.
The robot device according to any one of claims 1 to 3,
comprising a position detection unit that detects the position of the robot main body,
The robot body is a robot body of a medical robot used for patient diagnosis and treatment,
The control unit controls the drive unit so that the robot body operates based on the assumed thigh position of the patient, and the position detection unit controls the drive unit when an external force acting on the robot body is detected. changing the thigh position based on the position of the robot body detected by;
robotic equipment.
The robot device according to any one of claims 1 to 4,
The control unit terminates the evacuation operation when the robot body enters a restricted area set within the movable area due to the evacuation operation in the safe state.
robotic equipment.
The robot device according to claim 5,
comprising a position detection unit that detects the position of the robot main body,
The control unit sets the restricted area to a predetermined range whose boundary is the position of the robot body detected by the position detection unit when the external force detection unit detects an external force acting on the robot body.
robotic equipment.
The robot device according to any one of claims 1 to 6,
The control unit controls the robot body when a predetermined period of time has elapsed since the transition to the safe state, when the amount of movement of the robot body in the retreat operation exceeds a predetermined amount in the safe state, or when the robot body moves in the safe state. terminating the evacuation operation when the moving speed in the evacuation operation exceeds a predetermined speed;
robotic equipment.
The robot device according to any one of claims 1 to 7,
The robot main body has an arm,
The drive unit includes a motor that drives a joint shaft of the arm,
The external force detection unit detects an angular velocity of the joint axis or a torque acting on the joint axis as an external force acting on the robot body,
The control unit controls the drive unit in the safe state so that an additional torque corresponding to the detected angular velocity or torque is output from the corresponding motor in the direction of the detected angular velocity or torque.
robotic equipment.
The robot device according to any one of claims 1 to 7,
The robot main body has an arm,
The drive unit includes a motor that drives a joint shaft of the arm,
The external force detection unit includes a force sensor provided on the arm,
The control unit controls the drive unit in the safe state so that an additional torque according to the detected value of the force sensor is output from the corresponding motor in the direction of the detected external force.
robotic equipment.
an ultrasonic probe,
a robot body that holds the ultrasonic probe in its hand;
a drive unit that drives the robot body;
an external force detection unit that detects an external force acting on the robot body;
a control unit that controls the drive unit to move to a safe state so that the robot body moves in a predetermined direction when an external force acting on the robot body is detected by the external force detection unit;
An ultrasonic diagnostic system equipped with