Tactile sensor, sensitivity switching circuit and sensitivity switching method

Abstract

The present invention aims to provide a tactile sensor, a sensitivity switching circuit, and a sensitivity switching method that can obtain force resolution corresponding to the object being processed and can handle both low and high load conditions. The tactile sensor is mounted on the hand of a robot and includes: an acquisition component for acquiring at least one of visual information and tactile information, wherein the visual information is object information related to an object manipulated by the hand, and the tactile information is object information when the object is grasped by the hand; and a control device for changing the sensitivity mode of the tactile sensor based on the acquired object information.

Description

Technical Field

[0001] This invention relates to a tactile sensor, a sensitivity switching circuit, and a sensitivity switching method. Background Technology

[0002] For example, a technology has been developed that allows operators to feel the robot's operation when using remote control. In this case, tactile sensors are installed on the robot's robotic hand, and the tactile information detected by the sensors is fed back to the operator (see, for example, Patent Document 1). In the robotic hand, to achieve dexterity and grip strength, the tactile sensors mounted on the hand require both high sensitivity and a wide dynamic range.

[0003] In this system, an analog-to-digital (A / D) converter is used to digitize the analog data from the resistive tactile sensor for data processing. Figure 16 This is a diagram illustrating an example of the circuit structure of a conventional tactile sensor system. For example... Figure 16 As shown, the output of sensor 901 is input to amplifier circuit 902. Sensor 901 is a resistive type, whose resistance changes according to the applied force. Amplifier circuit 902 amplifies the output of sensor 901 and outputs it to central processing unit (CPU) 903. CPU 903 has an analog-to-digital converter (ADC) 904. ADC 904 digitizes the analog data output from amplifier circuit 902 for data processing.

[0004] [Existing Technical Documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-198939 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] Figure 17 This is a graph illustrating the relationship between force and the input voltage of an ADC in previous technologies. The vertical axis represents the voltage value, and the horizontal axis represents the force. Figure 16 The ADC904 described herein has a resolution of, for example, 10 bits. In conventional technology, when the sensor 901 is resistive, such as... Figure 12As shown, resolution can be improved in regions with low force (low load) and low voltage, but the resolution becomes coarser in regions with high force (high load) and high voltage.

[0009] In the past, the resolution of AD converters depended on the device. If the voltage gain was set in order to measure a wide dynamic range from low load to high load, the force resolution became coarse, making it difficult to perform fine force control in the low load range (high sensitivity side).

[0010] The present invention was made in view of the aforementioned problems, and aims to provide a tactile sensor, a sensitivity switching circuit, and a sensitivity switching method that can obtain a force resolution corresponding to the object being processed and can handle both low and high load conditions.

[0011] [Technical means to solve the problem]

[0012] (1) In order to achieve the above objective, a tactile sensor according to an embodiment of the present invention includes: an acquisition component for acquiring at least one of visual information and tactile information, wherein the visual information is object information related to an object to be operated by the hand, and the tactile information is object information when the object to be operated by the hand is grasped; and a control device for changing the sensitivity mode of the tactile sensor according to the acquired object information.

[0013] (2) Moreover, in a tactile sensor of an embodiment of the present invention, the control device may detect the weight of the object based on the tactile information, compare the detected weight with the weight of the object imagined in the switched sensitivity mode, and change the sensitivity mode based on the comparison result.

[0014] (3) Furthermore, in a tactile sensor according to an embodiment of the present invention, the acquisition component may include: an analog-to-digital converter that converts the object information, which is analog data, into digital data; and an amplification unit that can change the gain of the analog data relative to the signal. The control device dynamically changes the gain or threshold of the amplification unit when the robot moves in response to the analog data input to the analog-to-digital converter, thereby changing the sensitivity mode.

[0015] (4) Moreover, in a tactile sensor of an embodiment of the present invention, the control device may maintain the force before the start of the switching during the switching of the sensitivity mode, and after the switching of the sensitivity mode, switch to the force calculated by the force conversion formula after switching to the sensitivity mode.

[0016] (5) To achieve the above objective, a sensitivity switching circuit according to an embodiment of the present invention includes: a comparison amplifier circuit for comparing and amplifying the voltage value output by a tactile sensor mounted on the hand of a robot with a reference voltage value; a gain variable resistor for making the gain of the comparison amplifier circuit variable according to a sensitivity mode switching instruction of the tactile sensor; a reference voltage variable resistor for making the voltage value output by the tactile sensor variable according to a sensitivity mode switching instruction of the tactile sensor; and an analog-to-digital converter for converting the analog value output by the comparison amplifier circuit into a digital value.

[0017] (6) In order to achieve the above objective, an embodiment of the present invention provides a sensitivity switching method for a tactile sensor installed on the hand of a robot, wherein an acquisition component acquires at least one of visual information and tactile information, wherein the visual information is object information related to an object operated by the hand, and the tactile information is object information when the object operated by the hand is grasped, and the control device changes the sensitivity mode of the tactile sensor according to the acquired object information.

[0018] [The effects of the invention]

[0019] According to (1) to (6), the sensitivity mode is switched based on at least one of visual information and tactile information, so that the force resolution corresponding to the object being processed can be obtained and both low load and high load conditions can be handled. Attached Figure Description

[0020] Figure 1 This is a diagram that shows an overview of the implementation method.

[0021] Figure 2 This is a diagram illustrating a structural example of the robotic arm according to the first embodiment.

[0022] Figure 3 This is a diagram illustrating a structural example of a robot including a tactile sensor according to the first embodiment.

[0023] Figure 4 This is a diagram showing a structural example of the joint control unit in the first embodiment.

[0024] Figure 5 This is a diagram showing an example of a sensitivity table according to the first embodiment.

[0025] Figure 6 This is a flowchart of an example of the robot's processing flow in the first embodiment.

[0026] Figure 7 This is a diagram illustrating examples of the high-sensitivity mode and wide-range mode of the first embodiment.

[0027] Figure 8 This is a diagram illustrating an example of the gain switching process in the high-sensitivity mode of the first embodiment.

[0028] Figure 9 This is a diagram illustrating an example of the gain switching process in the wide-range mode of the first embodiment.

[0029] Figure 10 This is a diagram illustrating an example of the action during gain switching.

[0030] Figure 11 This is a diagram illustrating an example of the range of gain switching in a variant example.

[0031] Figure 12 This is a diagram showing an example of the correspondence between the switching mode, load range, resolution, object, gripping object, and action in the first embodiment.

[0032] Figure 13 This is a diagram showing the relationship between the load range and force range example of the first embodiment.

[0033] Figure 14 This is a diagram illustrating a structural example of a robot including a tactile sensor according to the second embodiment.

[0034] Figure 15 This is a flowchart of an example of the robot's processing flow in the second embodiment.

[0035] Figure 16 This is a diagram illustrating an example of the circuit structure of a conventional tactile sensor system.

[0036] Figure 17 This is a graph illustrating the relationship between force and input voltage value of the ADC in previous technologies.

[0037] [Explanation of Symbols]

[0038] 1. 1A: Robot

[0039] 3. 3A: Tactile sensor

[0040] 31: Robotic Arm

[0041] 33: Grip section

[0042] 331: Finger part

[0043] 331a: Thumb

[0044] 331b: Index finger

[0045] 331c: Middle finger

[0046] 21, 21-11, 21-12, 21-21, 21-22, 21-31, 21-32, 21-41, 21-42, 21-51, 21-52, ..., 21-n1, 21-n2: Sensors

[0047] 11: Filming equipment

[0048] 13: Object Recognition Unit

[0049] 15, 15A: Robot Control Department

[0050] 17: Sensor Control Unit

[0051] 17-1: First Sensor Control Unit

[0052] 17-2: Second Sensor Control Unit

[0053] …

[0054] 17-n: nth sensor control unit

[0055] 19, 19-11, 19-12, 19-21, 19-22, ..., 19-n1, 19-n2: Joint control units

[0056] 23: Ministry of Communications

[0057] 192: Comparator Amplifier Circuit

[0058] 193: ADC Detailed Implementation

[0059] The following is a reference to the appendix. Figure 1 The embodiments of the present invention will be described below. Additionally, the scale of each component in the accompanying drawings used in the following description has been appropriately altered to make each component a recognizable size.

[0060] [summary]

[0061] First, a summary of the implementation method will be provided.

[0062] Figure 1 This diagram illustrates an overview of the implementation method. In this implementation, objects are identified based on visual information (object information), and the sensitivity of the tactile sensor is switched based on the identification result. Alternatively, this implementation identifies objects based on visual information (object information), switches the sensitivity of the tactile sensor based on the identification result, and then corrects the sensitivity based on tactile information (object information). Alternatively, this implementation may also use distance information or temperature information, etc., to switch (or correct) the sensitivity of the tactile sensor.

[0063] The object is like the region g1 enclosed by the chain, such as a light object, a soft object, a small object, a hard object, a heavy object, a child or an infant, etc.

[0064] The sensitivity of a tactile sensor can be, for example, in a high-sensitivity mode or a wide-range sensitivity mode. The tasks performed by the robotic arm, such as within the area g2 enclosed by the chain, include gently stroking a child's head, switching hands to pick up an object, picking up a light object, picking up a heavy object, and opening a bottle cap. Examples of suitable high-sensitivity modes include gently stroking a child's head, switching hands to pick up an object, and picking up a light object. Examples of suitable wide-range modes include picking up a heavy object. Furthermore, in-hand manipulation refers to tasks performed while holding the object and switching hands.

[0065] <First Implementation>

[0066] In this embodiment, the sensitivity of the tactile sensor is switched based on visual information.

[0067] [Example of a robotic arm's structure]

[0068] Figure 2 This is a diagram illustrating an example of the structure of the robotic arm according to this embodiment. (See diagram for example.) Figure 2 As shown, the robotic hand 31 includes a gripping part 33. The gripping part 33 includes, for example, five fingers 331 (thumb 331a, index finger 331b, and middle finger 331c). Each finger 331 includes multiple joints and knuckles. Moreover, sensors 21 (acquisition components) are respectively installed on the knuckles of the fingers (sensor 21-11 (acquisition component), sensor 21-12 (acquisition component), sensor 21-21 (acquisition component), sensor 21-22 (acquisition component), sensor 21-31 (acquisition component), sensor 21-32 (acquisition component), sensor 21-41 (acquisition component), sensor 21-42 (acquisition component), sensor 21-51 (acquisition component), and sensor 21-52 (acquisition component)).

[0069] in addition, Figure 2 The structure described herein is one example, but the structure of the robotic arm 31 is not limited to this. For example, the number of fingers 331 is not limited to five; two or more are sufficient. Furthermore, the sensor 21 may be installed only on the first phalanx (the fingertip).

[0070] [Example of robot structure]

[0071] Figure 3 This is a diagram illustrating a structural example of a robot including a tactile sensor according to this embodiment. (See diagram for details.) Figure 3 As shown, robot 1 includes a camera 11 (acquisition component), an object recognition unit 13 (acquisition component), and a tactile sensor 3.

[0072] The tactile sensor 3 includes, for example, a robot control unit 15 (control device, acquisition component), a first sensor control unit 17-1, a second sensor control unit 17-2, ..., an nth sensor control unit 17-n, a joint control unit 19-11, a joint control unit 19-12, a joint control unit 19-21, a joint control unit 19-22, ..., a joint control unit 19-n1, a joint control unit 19-n2, a sensor 21-11, a sensor 21-12, a sensor 21-21, a sensor 21-22, ..., a sensor 21-n1, a sensor 21-n2, and a communication unit 23.

[0073] Additionally, robot 1 includes a power supply unit (not shown) that supplies power to each part. Furthermore, in the following description, unless one of the first sensor control unit 17-1, the second sensor control unit 17-2, ..., the nth sensor control unit 17-n is specifically designated, it will be referred to as "sensor control unit 17". Moreover, unless one of the joint control units 19-11, 19-12, 19-21, 19-22, ..., 19-n1, and 19-n2 is specifically designated, it will be referred to as "joint control unit 19".

[0074] The shooting device 11 includes, for example, a red-green-blue (RGB) camera and a depth sensor.

[0075] The object recognition unit 13 detects object information such as the three-dimensional position, size, and shape of objects in the captured image using well-known methods, based on the captured image and the detection results obtained by the sensor. The object recognition unit 13 performs image processing (edge ​​detection, binarization, feature extraction, image enhancement, image extraction, pattern matching, etc.) on the captured image, referring to its stored pattern matching models, to infer the object name. Furthermore, when multiple objects are detected in the captured image, the object recognition unit 13 detects object information for each object.

[0076] The robot control unit 15 determines whether to switch the sensitivity of sensor 21 based on the visual information recognized by object recognition unit 13 and its stored sensitivity table. The sensitivity table will be described later. Based on the determination result, the robot control unit 15 generates a sensitivity adjustment command and outputs the generated sensitivity adjustment command to the first sensor control unit 17-1. Furthermore, the sensitivity adjustment command may also include object information for the sensor 21, which is the controlled object.

[0077] The sensor control unit 17 acquires a sensitivity adjustment command. The sensor control unit 17 acquires the detection data detected by the sensor, which is converted into digital data by the joint control unit. The sensor control unit 17 outputs the detection data to the robot control unit 15.

[0078] The first sensor control unit 17-1 outputs the sensitivity adjustment command from the robot control unit 15 to the joint control units 19-11, 19-12, and the second sensor control unit 17-2. The first sensor control unit 17-1 acquires the detection data output by the joint control units 19-11 and 19-12 respectively, and outputs the acquired detection data to the second sensor control unit 17-2.

[0079] The second sensor control unit 17-2 outputs the sensitivity adjustment command output by the first sensor control unit 17-1 to the joint control units 19-21, 19-22, and the third sensor control unit 17-3 (not shown). The second sensor control unit 17-2 acquires the detection data output by the joint control units 19-21 and 19-22 respectively, and the detection data output by the first sensor control unit 17-1, and outputs the acquired detection data to the third sensor control unit 17-3.

[0080] The nth sensor control unit 17-n outputs the sensitivity adjustment command output by the first sensor control unit 17-(n-1) (not shown) to the joint control units 19-n1 and 19-n2. The nth sensor control unit 17-n acquires the detection data output by the joint control units 19-n1 and 19-n2 respectively, and the detection data output by the second sensor control unit 17-2, and outputs the acquired detection data to the robot control unit 15.

[0081] The joint control unit 19 switches the sensitivity of the sensor 21 according to the sensitivity adjustment command. Furthermore, the structure and operation of the joint control unit 19 will be described later.

[0082] Sensor 21 is a tactile sensor that detects force applied to an object (pressure applied by a finger). Additionally, sensor 21 may also include a joint control unit 19.

[0083] [Structural example of joint control unit 19]

[0084] The following describes a structural example of the joint control unit 19.

[0085] Figure 4 This is a diagram illustrating an example of the structure of the joint control unit in this embodiment. (See diagram for example.) Figure 4As shown, the joint control unit 19 includes, for example, a variable resistor R1 (reference voltage variable resistor), resistors R2 and R3, a variable resistor R4 (first gain resistor, gain variable resistor), a variable resistor R5 (second gain resistor, gain variable resistor), a DAC (digital-to-analog converter) 191, a comparator amplifier circuit 192, and an ADC 193. Additionally, Figure 4 The structure of the joint control unit 19 shown is an example, and is not limited thereto.

[0086] One end of sensor 21 is connected to voltage Vdd, and the other end is connected to one end of variable resistor R1 and one end of resistor R3.

[0087] The other end of the variable resistor R1 is grounded, and the resistance value r is determined by adjustment data representing the adjustment amount based on the sensitivity adjustment command. ref variable.

[0088] The input terminals of the DAC191 are used to input adjustment data, and the output terminals are connected to one end of R2.

[0089] The other end of resistor R2 is connected to the negative input terminal of comparator amplifier circuit 192 and one end of variable resistor R4.

[0090] The other end of resistor R3 is connected to the positive input terminal of comparator amplifier circuit 192 and one end of variable resistor R5.

[0091] The other end of the variable resistor R4 is connected to the output terminal of the comparator amplifier circuit 192 and the input terminal of the ADC. The resistance value r is adjusted by changing the data. g2_1 variable.

[0092] The other end of the variable resistor R5 is grounded, and the resistance value r is adjusted by changing the data. g2_2 variable.

[0093] The variable resistors R1, R4, and R5 are, for example, digital potentiometers. Furthermore, the adjustment data is transmitted from the joint control unit 19 to each unit via, for example, serial communication (I2C).

[0094] Here, let the resistance value of sensor 21 be r. s The resistance of variable resistor R1 is rref, the resistance of resistor R2 is Rg1, the resistance of resistor R3 is Rg1, and the resistance of variable resistor R4 is r. g2_1 (=r g 2) The resistance value of the variable resistor R5 is r. g2_2 (=r g2 Furthermore, let the output voltage of DAC191 be Vref.

[0095] The output voltage Vout of sensor 21 is expressed by the following formula (1).

[0096] [Number 1]

[0097]

[0098] Furthermore, the input voltage Vadc of ADC193 is expressed by the following equation (1).

[0099] [Number 2]

[0100]

[0101] [Example of a sensitivity meter]

[0102] The following section provides an example of a sensitivity table.

[0103] Figure 5 This is a diagram illustrating an example of a sensitivity table according to this embodiment. For example... Figure 5 As shown, in the sensitivity table, for example, the sensitivity mode, the resistance value of the first gain resistor, the resistance value of the second gain resistor, and the resistance value of the reference voltage variable resistor are associated with the object name.

[0104] in addition, Figure 5 The sensitivity table shown is an example and is not limited to this.

[0105] [Processing Flow Example]

[0106] The following describes an example of the processing flow for robot 1.

[0107] Figure 6 This is a flowchart of an example of the robot's processing flow in this embodiment.

[0108] (Step S1) The object recognition unit 13 processes the image captured by the imaging device 11 using well-known methods to identify object information such as the object's position, size, and name.

[0109] (Step S2) The robot control unit 15 selects the sensitivity mode based on the result identified by the object recognition unit 13.

[0110] (Step S3) The robot control unit 15 determines whether the selected sensitivity mode is different from the initial mode. If the robot control unit 15 determines that the selected sensitivity mode is different from the initial mode (Step S3; Yes), it proceeds to the process of step S4. If the robot control unit 15 determines that the selected sensitivity mode is not different from the initial mode (Step S3; No), it proceeds to the process of step S5.

[0111] (Step S4) The robot control unit 15 switches to the selected sensitivity mode.

[0112] (Step S5) The robot control unit 15 performs control to bring the robotic arm 31 closer to the object (object approach).

[0113] (Step S6) The robot control unit 15 controls the robotic arm 31 to pick up the object.

[0114] (Step S7) The robot control unit 15 controls the robotic arm 31 to perform the prescribed task (e.g., manual operation).

[0115] (Step S8) The robot control unit 15 controls the robotic arm 31 to place the object (release, put down).

[0116] (Step S9) The robot control unit 15 determines whether the sensitivity mode has been switched. If the robot control unit 15 determines that the sensitivity mode has been switched (Step S9; Yes), the process proceeds to step S10. If the robot control unit 15 determines that the sensitivity mode has not been switched (Step S9; No), the process ends.

[0117] (Step S10) The robot control unit 15 switches to sensitivity mode and returns to the initial mode.

[0118] [Example of handling sensitivity switching]

[0119] The following section provides an example of sensitivity switching.

[0120] Figure 7 These are diagrams illustrating examples of the high-sensitivity mode and wide-range mode of this embodiment. Graph g101 shows the relationship between force and input voltage to the ADC193 in high-sensitivity mode. Graph g102 shows the relationship between force and input voltage to the ADC193 in wide-range mode. In graphs g101 and g102, the horizontal axis represents force, and the vertical axis represents voltage value. Furthermore, it is assumed that the resolution of the ADC193 is 10 bits.

[0121] As shown in Table g101, the high-sensitivity mode is used, for example, when the force is less than a specified value. Furthermore, by adjusting the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor, 10 bits are applied to, for example, threshold voltages Vth to V1. Alternatively, in high-sensitivity mode, 10 bits are applied to, for example, voltage values ​​Vth to V2. Additionally, the threshold voltage Vth can be variable. Thus, even in high-sensitivity mode, multiple combinations of the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor can exist.

[0122] As shown in Table g102, the wide-range mode is used, for example, when the force is above a specified value. Furthermore, by adjusting the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor, 10 bits are applied to, for example, threshold voltages Vth to V11. Alternatively, in the wide-range mode, 10 bits are applied to, for example, voltage values ​​Vth to V13. Additionally, the threshold voltage Vth can be variable. Thus, even in the wide-range mode, multiple combinations of the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor can exist.

[0123] As shown in Figure g101 and Figure g102, in high sensitivity mode, the range of input voltage to ADC193 is wider than in wide range mode, and the range of force f1 is narrower than in wide range mode.

[0124] As shown in Table g101 and Chart g102, in wide-range mode, the force range f 11 It has a wider range of input voltages for the ADC193 than the high-sensitivity mode.

[0125] in addition, Figure 7 The ranges of voltages, threshold voltages, and forces shown are examples and are not limited to these.

[0126] The following describes an example of the gain switching process in high-sensitivity mode.

[0127] Figure 8 This is a diagram illustrating an example of the gain switching process in the high-sensitivity mode of this embodiment. In graphs g151 and g152, the horizontal axis represents force, and the vertical axis represents voltage value.

[0128] Chart g151 shows the chart before mode switching. Let the relationship between voltage V and force f be V = g(f), and let the threshold voltage Vth be 0 (V). Here, let the detection frequency band to be detected by sensor 21 be f1.

[0129] Chart g152 is the chart after the mode switch.

[0130] In high-sensitivity mode, the relationship between voltage V and force f when the gain is, for example, twice, is V = gain × (g(f) - Vth) = 2 × g(f).

[0131] The following describes an example of the gain switching process in wide-range mode.

[0132] Figure 9 This is a diagram illustrating an example of the gain switching process in the wide-range mode of this embodiment. In graphs g171, g172, and g173, the horizontal axis represents force, and the vertical axis represents voltage value.

[0133] Chart g171 shows the chart before mode switching. Let the relationship between voltage V and force f be V = g(f). Here, let the detection frequency band to be detected by sensor 21 be f1~f2.

[0134] Chart g172 is the chart after the mode switch.

[0135] In wide-range mode, the relationship between voltage V and force f when the gain is, for example, five times, is V = gain × (g(f) - Vth) = 5 × (g(f) - Vth).

[0136] Here, the adjustment data for the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor are input serially, for example. Therefore, there may be a time difference in the timing of changes in the resistance values ​​of the first gain resistor, the second gain resistor, and the reference voltage variable resistor. Furthermore, due to current changes caused by the analog circuit or chattering from the switching action of the switching components, the output voltage V may differ before and after gain switching, even when the same force f1 is applied. As a result, the voltage may momentarily become unstable during analog circuit switching. Consequently, malfunctions may occur in the object grip control (force control).

[0137] Figure 10 This is a diagram illustrating an example of the action during gain switching.

[0138] Chart g201 illustrates the time difference and instability region caused by communication during gain switching, with the horizontal axis representing time and the vertical axis representing voltage. At time t1, the threshold voltage Vth switches, and the period T2 from time t1 to time t2 is the unstable region. At time t3, the resistance value of the first gain resistor switches, and the period T3 from time t3 to time t4 is the unstable region. At time t5, the resistance value of the second gain resistor switches, and the period T4 from time t4 to time t6 is the unstable region. Furthermore, the period T1 from time t1 to time t7 represents the set time difference caused by communication.

[0139] As shown in Table g201, due to the gain switching, the original intention was to switch from the voltage value Vb to Va, but the change occurred in stages and included periods of instability.

[0140] Chart g202 illustrates the relationship between time and force during gain switching as shown in Chart 201. The horizontal axis represents time, and the vertical axis represents force. As shown in Chart g202, the force used for the value is fixed at f1, but the force during the gain switching period T1 is not fixed. Therefore, if the data for the period T1 is used as control data, it is prone to malfunctions and cannot be used. Furthermore, the force conversion formula for the period from time t1 to time t7 is f = g. -1(V) is used to represent the force after time t7, and the force conversion formula is f = g. -1 (V / G+Vth) can be used to represent this.

[0141] In contrast, in this embodiment, as shown in graph g173, the force f1 before the start of the switch is maintained during the set time difference caused by communication (the switching period). Graph g173 is a graph showing the relationship between force and time during gain switching in this embodiment. Therefore, the force conversion up to time t1 is expressed as f = g -1 (V) is used to represent the force during the period from time t1 to time t7, and the force conversion formula is represented by f = f1. The force conversion formula after time t7 is represented by f = g. -1 (V / G+Vth) can be used to represent this.

[0142] Through this processing, according to this embodiment, the effects of time differences caused by communication during gain switching, the effects of switch chatter, and the effects of current changes caused by analog circuits can be prevented. Furthermore, the robot control unit 15 can dynamically change the gain switching and threshold switching via communication during the operation of the robot 1.

[0143] [Variation Example]

[0144] Furthermore, the examples described herein illustrate two gain modes: high sensitivity mode and wide range mode. However, there can be more than two gain modes. In this case, such as Figure 11 As shown, relative to force f, it can also have several ranges.

[0145] Figure 11 This is a diagram illustrating an example of the range of gain switching in a variant example. Figure 11 In the diagram, the horizontal axis represents force, and the vertical axis represents the input voltage to the ADC. Mode I covers the force range f0 to f6. Modes II and III use two modes to cover the force range f0 to f6. Modes IV to VII use four modes to cover the force range f0 to f6. Mode VIII covers a portion of the force range f2 to f5, specifically f0 to f6. Mode IX covers a portion of the force range f1 to f4, specifically f0 to f6.

[0146] Robot control unit 15, for example, like Figure 12 In that way, switching is based on the identified object. Figure 11 The multiple modes shown. Figure 12 This diagram illustrates the correspondence between the switching mode, load range, resolution, object, gripping object, and action in this embodiment. Additionally, the robot control unit 15 stores... Figure 12 The relationship. Alternatively, the robot control unit 15 can also acquire and store the data via a network or the like.

[0147] like Figure 12 As shown, for example, Mode I is: the load range is "low to high", the resolution is "low", the object is "heavy objects. Coarse processing can also be performed. In cases of large load changes", etc., the object being held is "2L plastic bottle, rice bag", etc., and the action is "open the bottle cap and pour water into the 2L plastic bottle", etc.

[0148] Furthermore, for example, mode V is: the load range is "low to medium", the resolution is "high", the object is "something with a slightly low load and requiring delicate processing, such as precision machinery", and the object being held is "an egg, a smartphone, a remote control", etc.

[0149] Furthermore, for example, Mode IX is: the load range is "medium", the resolution is "medium", the object is "a medium load area where the load will change to a certain extent", and the action is "gently stroking a child", etc.

[0150] Figure 13 This is a graph showing the relationship between the load range and force range example of this embodiment. For example... Figure 13 As shown, the force range for a "low" load range is, for example, "0.01 (N) to 0.5 (N), 1 (g) to 50 (g)". The force range for a "low-medium" load range is, for example, "0.5 (N) to 0.2 (N), 50 (g) to 200 (g)". The force range for a "medium-high" load range is, for example, "2 (N) to 10 (N), 200 (g) to 10 (kg)". The force range for a "high" load range is, for example, "more than 10 (N), more than 10 (kg)".

[0151] in addition, Figure 11 , Figure 12 The switching mode shown is an example, and is not limited to this. Furthermore, Figure 12 The load range, resolution, object, held object, and action shown in the switching mode are examples, and are not limited to these. Figure 13 The force range of the load range shown is just one example, and is not limited to this. Moreover, each range can be either fixed or variable. In addition, when the range width is set to be variable, the range can be varied, for example, based on the actual detected value of sensor 21.

[0152] Furthermore, the robot control unit 15 can also predict future changes in state or action to adjust the range. For example, when holding a cup and pouring water into or out of it, the robot control unit 15 can make predictions based on the results of environmental recognition using visual information.

[0153] As described above, in this embodiment, the sensitivity of the ADC193, the output of the input sensor 21, is switched based on the object identified based on visual information. Furthermore, in this embodiment, the sensitivity mode is switched using gain switching and reference voltage switching. Moreover, in this embodiment, the force is kept constant during the switching timing caused by communication during mode switching.

[0154] Therefore, according to this embodiment, force resolution corresponding to the object being processed can be obtained, thereby enabling both dexterous and powerful operations to be performed using the same system. Furthermore, according to this embodiment, malfunctions caused by deviations in switching timing due to communication issues during switching can be prevented.

[0155] <Second Implementation>

[0156] In this embodiment, the sensitivity of the tactile sensor is switched based on visual and tactile information.

[0157] (Example of robot structure)

[0158] Figure 14 This is a diagram illustrating a structural example of a robot including sensors according to this embodiment. (See diagram for example.) Figure 14 As shown, robot 1A includes a camera 11 (acquisition component), an object recognition unit 13 (acquisition component), and a tactile sensor 3A.

[0159] The tactile sensor 3A includes, for example, a robot control unit 15A (control device, acquisition component), a first sensor control unit 17A-1, a second sensor control unit 17A-2, ..., an nth sensor control unit 17A-n, a joint control unit 19A-11, a joint control unit 19A-12, a joint control unit 19A-21, a joint control unit 19A-22, ..., a joint control unit 19A-n1, a joint control unit 19A-n2, a sensor 21-11, a sensor 21-12, a sensor 21-21, a sensor 21-22, ..., a sensor 21-n1, a sensor 21-n2, and a communication unit 23.

[0160] Additionally, robot 1A includes a power supply unit (not shown) that supplies power to each part. Furthermore, in the following description, unless one of the first sensor control unit 17A-1, the second sensor control unit 17A-2, ..., the nth sensor control unit 17A-n is specifically designated, it will be referred to as "sensor control unit 17A". Moreover, unless one of the joint control units 19A-11, 19A-12, 19A-21, 19A-22, ..., 19A-n1, and 19A-n2 is specifically designated, it will be referred to as "joint control unit 19A".

[0161] The joint control unit 19A acquires tactile information detected by the sensor 21 when the object is grasped, and outputs the acquired tactile information to the sensor control unit 17A. Furthermore, the circuit structure of the joint control unit 19A is, for example, similar to that of the first embodiment. Figure 4 same.

[0162] The sensor control unit 17A outputs the acquired tactile information to the robot control unit 15A.

[0163] The robot control unit 15A first switches the sensitivity mode based on visual information, similar to the first embodiment. Next, the robot control unit 15A determines whether to adjust the sensitivity based on tactile information during actual gripping, and adjusts the sensitivity based on the determination result.

[0164] [Processing Flow Example]

[0165] The following describes an example of the processing flow for robot 1A.

[0166] Figure 15 This is a flowchart of an example of the robot's processing flow in this embodiment.

[0167] (Steps S1 to S6) Robot 1A performs the processing of steps S1 to S5.

[0168] (Step S101) The robot control unit 15A detects the weight of the object being held using a well-known method based on tactile information during actual gripping.

[0169] (Step S102) The robot control unit 15A determines whether the weight is consistent with the assumption of the sensitivity mode switched based on visual information (e.g., referring to...). Figure 13 If the robot control unit 15A determines that the weight is consistent with the expected weight (step S102; yes), then the processing steps S7 to S10 are performed. If the robot control unit 15A determines that the weight is not consistent with the expected weight (step S102; no), then the processing step S103 is performed.

[0170] (Step S103) The robot control unit 15A determines whether the weight of the object being held is lighter than expected. If the robot control unit 15A determines that the weight of the object being held is lighter than expected (Step S103; Yes), then proceed to step S104. If the robot control unit 15A determines that the weight of the object being held is not lighter (heavier) than expected (Step S103; No), then proceed to step S105.

[0171] (Step S104) The robot control unit 15A increases the sensitivity relative to the switched sensitivity mode. After processing, the robot control unit 15A returns to the processing in step S6.

[0172] (Step S105) The robot control unit 15A reduces the sensitivity relative to the switched sensitivity mode. After processing, the robot control unit 15A returns to the processing in step S6.

[0173] in addition, Figure 15 The processing flow shown is an example and is not limited to this. For example, in step S103, the robot control unit 15A can also determine whether it is heavier than expected. In this case, the robot control unit 15A can also reduce the sensitivity if it is heavier than expected, and increase the sensitivity if it is not heavier than expected.

[0174] Furthermore, the robot control unit 15A can also adjust the sensitivity mode, for example, by... Figure 11 The robot control unit 15A can switch from mode II to mode IV or mode VI, thereby increasing or decreasing sensitivity. Alternatively, the robot control unit 15A can also be configured to, for example... Figure 11 Use Mode II to fine-tune the sensitivity mode, thereby increasing or decreasing the sensitivity.

[0175] Furthermore, in this embodiment, similar to the first embodiment, the sensitivity mode is switched using gain switching and reference voltage switching. Moreover, in this embodiment, the force remains fixed during the switching timing caused by communication during mode switching.

[0176] Therefore, according to this embodiment, a sensitivity mode corresponding to the contact object is set based on visual and tactile information, so the resolution of the force corresponding to the object being processed can be obtained with better accuracy, thereby enabling both dexterous and powerful operations to be performed using the same system.

[0177] Furthermore, in the various embodiments and variations described above, the robot only needs to include a robotic arm, and can also be a bipedal robot, a work robot, a service robot, a nursing robot, etc. Moreover, the robotic arm in the various embodiments and variations only needs to include at least two fingers.

[0178] Furthermore, while the various embodiments and modifications described herein have used the motion control of a single robotic arm as an example, there can be two or more robotic arms. In this case, the robot control unit 15 (or 15A) can switch the sensitivity modes of each robotic arm based on visual information. For example, the robot control unit 15 (or 15A) can switch the sensitivity modes of the first and second robotic arms to the same sensitivity mode, or it can switch them to different sensitivity modes.

[0179] Furthermore, the robot control unit 15A can also adjust the sensitivity modes of the first and second robotic hands to be the same, or to be different, based on the tactile information of actual gripping.

[0180] Furthermore, the robot control unit 15 (or 15A) can also switch sensitivity modes based on tactile information. Additionally, the robot control unit 15 (or 15A) can also adjust the sensitivity mode switched based on tactile information based on visual information.

[0181] Alternatively, all or part of the program used to implement the functions of robot 1 (or 1A) in this invention can be recorded on a computer-readable recording medium, allowing the computer system to read and execute the program recorded on the recording medium, thereby performing all or part of the processing performed by robot 1 (or 1A). Furthermore, the term "computer system" as used herein includes hardware such as an operating system (OS) or peripheral machines. Moreover, "computer system" also includes systems built on a local area network or systems built in the cloud. Furthermore, "computer-readable recording medium" refers to removable media such as floppy disks, optical disks, read-only memory (ROM), and compact disc read-only memory (CD-ROM), and storage devices such as hard drives built into a computer system. Furthermore, "computer-readable recording medium" also includes servers that send programs via networks such as the Internet or communication lines such as telephone lines, or memory that holds programs for a certain period of time, such as volatile memory (random access memory) within a computer system that acts as a client.

[0182] Furthermore, the program can also be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium, or via transmission waves in the transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium with information transmission capabilities, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line. Moreover, the program can also be a component used to implement the aforementioned functions. Furthermore, it can also be a so-called differential file (differential program) capable of implementing the aforementioned functions through combination with a program already recorded in the computer system.

[0183] The above describes the specific implementation method, but the present invention is not limited to this implementation method in any way, and various modifications and substitutions can be made without departing from the spirit of the present invention.

Claims

1. A tactile sensor, mounted on the hand of a robot, the tactile sensor comprising: The acquisition component acquires at least one of visual information and tactile information, wherein the visual information is object information identified by a visual sensor and related to an object operated by the hand, and the tactile information is object information detected when the object operated by the hand is grasped. as well as A control device changes the sensitivity mode of the tactile sensor based on at least one of the acquired visual information and tactile information. The control device detects the weight of the object based on the tactile information, compares the detected weight of the object with the weight of the object imagined in the switched sensitivity mode, and increases the sensitivity of the tactile sensor if the detected weight of the object is less than the weight of the object imagined in the switched sensitivity mode.

2. The tactile sensor according to claim 1, wherein... The hand includes a plurality of fingers equipped with the tactile sensors; The control device includes a robot control unit for switching the sensitivity mode, and a joint control unit for switching the sensitivity of the tactile sensors of each of the fingers respectively.

3. The tactile sensor according to claim 1 or 2, wherein The acquisition component includes: An analog-to-digital converter converts the visual and tactile information, which are analog data, into digital data. as well as The amplification section is capable of changing the gain of the analog data relative to the signal. The control device dynamically changes the gain or threshold of the amplification section when the robot moves in response to the analog data input to the analog-to-digital converter, thereby changing the sensitivity mode.

4. The tactile sensor according to claim 1 or 2, wherein The control device maintains the force before the start of the switching during the sensitivity mode switching period, and after the sensitivity mode switching period, switches to the force calculated by the force conversion formula after switching to the sensitivity mode. The force conversion formula is a formula that calculates the force in the sensitivity mode after the switch based on the output voltage, threshold voltage, gain of the tactile sensor and the force before the sensitivity mode switch begins.

5. A sensitivity switching method, which is a sensitivity switching method for a tactile sensor installed on the hand of a robot, wherein... The acquiring component acquires at least one of visual information and tactile information, wherein the visual information is object information identified by a visual sensor and related to an object manipulated by the hand, and the tactile information is object information detected when the object is grasped by the hand. The control device changes the sensitivity mode of the tactile sensor based on at least one of the acquired visual information and tactile information. The control device detects the weight of the object based on the tactile information, compares the detected weight of the object with the weight of the object imagined in the switched sensitivity mode, and increases the sensitivity of the tactile sensor if the detected weight of the object is less than the weight of the object imagined in the switched sensitivity mode.

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