Sensitivity switching circuit

Abstract

To provide a sensitivity switching circuit which includes resolution of power according to an object to be handled and is capable of coping with both low load and heavy load.SOLUTION: A sensitivity switching circuit comprises: a comparative amplification circuit, comparing and amplifying a voltage value output by a touch tactile sensor attached to a hand part of a robot with a reference voltage value; a gain variable resistance which varies a gain of the comparative amplification circuit according to an instruction for switching a sensitivity mode of the touch tactile sensor; a reference voltage variable resistance which varies the voltage value outputted from the tactile sensor according to the instruction for switching the sensitivity mode of the tactile sensor; an analogue-digital converter which converts an analogue value outputted from the comparative amplification circuit into a digital value.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a sensitivity switching circuit.

Background Art

[0002] For example, when an operator operates a robot remotely, technologies have been developed to make the operator feel the sensations of the robot's operation. In such a case, a tactile sensor is attached to the robot hand of the robot, and the tactile information detected by the tactile sensor is fed back to the operator (see, for example, Patent Document 1). In the robot hand, in order to achieve dexterity and strong gripping force, the tactile sensor mounted on the hand is required to have both high sensitivity and a wide dynamic range.

[0003] In such a system, analog data of a resistive tactile sensor is digitized by an AD converter (analog-digital conversion means) for data processing. FIG. 16 is a diagram showing a circuit configuration example of a conventional tactile sensor system. As shown in FIG. 16, the output of sensor 901 is input to amplifier circuit 902. Note that sensor 901 is a resistive type whose resistance value changes according to the applied force. Amplifier circuit 902 amplifies the output of sensor 901 and outputs it to a CPU (central processing unit) 903. CPU 903 has an ADC (AD converter) 904. ADC 904 digitizes the analog data output by amplifier circuit 902 for data processing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] FIG. 17 is a diagram showing an example of the relationship between the force according to the prior art and the input voltage value to the ADC. The vertical axis represents the voltage value, and the horizontal axis represents the force. Assume that the resolution of the ADC904 described in FIG. 16 is, for example, 10 bits. In the prior art, when the sensor 901 is resistive, as shown in FIG. X2, the resolution can be increased in the region where the force is small (low load) and the voltage value is low, but the resolution becomes rough in the region where the force is large (high load) and the voltage value is high.

[0006] In the prior art, the resolution of the AD converter depends on the device. When setting the voltage gain to measure a wide dynamic range from low load to high load, the force resolution becomes rough, and it is difficult to perform fine force control in the low load region (high sensitivity side).

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a sensitivity switching circuit capable of obtaining a force resolution corresponding to an object to be handled and being compatible with both low load and high load.

Means for Solving the Problems

[0008] (1) To achieve the above object, a sensitivity switching circuit according to an aspect of the present invention includes a comparison amplification circuit that compares and amplifies a voltage value output from a tactile sensor attached to a hand portion of a robot and a reference voltage value, a gain variable resistor that varies the gain of the comparison amplification circuit in response to an instruction to switch the sensitivity mode of the tactile sensor, a reference voltage variable resistor that varies the voltage value output from the tactile sensor in response to an instruction to switch the sensitivity mode of the tactile sensor to and an analog-to-digital converter that converts the analog value output from the comparison amplification circuit into a digital value.

Effects of the Invention

[0009] According to the above aspect, since the sensitivity mode is switched based on at least one of visual information and tactile information, a force resolution corresponding to an object to be handled can be obtained, and it is possible to cope with both low load and high load.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 4

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Figure 9

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Figure 11

Figure 12

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Figure 14

Figure 15

Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings used in the following description, the scale of each member is appropriately changed in order to make each member recognizable.

[0012] [Overview] First, the overview of the embodiment will be described. FIG. 1 is a diagram showing the overview of the embodiment. In this embodiment, an object is recognized based on visual information (target object information), and the sensitivity of the tactile sensor is switched based on the recognition result. Alternatively, in this embodiment, an object is recognized based on visual information (target object information), the sensitivity of the tactile sensor is switched based on the recognition result, and then the sensitivity is corrected based on tactile information (target object information). Or, in this embodiment, the sensitivity of the tactile sensor is switched (or corrected) using distance information, temperature information, etc. with respect to the object.

[0013] The object is, for example, a light object, a soft object, a small object, a hard object, a heavy object, a child or a baby, etc., like the region g1 surrounded by the dashed line. The sensitivity of the tactile sensor is, for example, a high-sensitivity mode and a wide-area sensitivity mode. The operations performed by the robot hand are, for example, gently stroking a child's head, changing the position of an object, holding a light object, holding a heavy object, opening the lid of a bottle, etc., like the region g2 surrounded by the dashed line. Examples of applying the high-sensitivity mode are, for example, gently stroking a child's head, changing the position of an object, holding a light object, etc. Examples of applying the wide-area mode are, for example, holding a heavy object, etc. Note that in-hand manipulation is, for example, an operation such as changing the position while holding an object.

[0014] [First Embodiment] In this embodiment, the sensitivity of the tactile sensor is switched based on visual information.

[0015] [Example of the Configuration of the Robot Hand] FIG. 2 is a diagram showing a configuration example of the robot hand according to the present embodiment. As shown in FIG. 2, the robot hand 31 includes a gripping part 33. The gripping part 33 includes, for example, five finger parts 331 (thumb 331a, index finger 331b, middle finger 331c). Each finger part 331 includes a plurality of joints and phalanges. In addition, sensors 21 (acquisition means) (sensors 21-11 (acquisition means), sensors 21-12 (acquisition means), sensors 21-21 (acquisition means), sensors 21-22 (acquisition means), sensors 21-31 (acquisition means), sensors 21-32 (acquisition means), sensors 21-41 (acquisition means), sensors 21-42 (acquisition means), sensors 21-51 (acquisition means), sensors 21-52 (acquisition means)) are attached, for example, to each phalanx of the finger.

[0016] Note that the configuration in FIG. 2 is an example, and the configuration of the robot hand 31 is not limited to this. For example, the number of finger parts 331 is not limited to five, and may be two or more. In addition, the sensor 21 may be attached only to the first phalanx (the belly of the fingertip).

[0017] [Configuration Example of Robot] FIG. 3 is a diagram showing a configuration example of a robot including a tactile sensor according to the present embodiment. As shown in FIG. 3, the robot 1 includes a photographing device 11 (acquisition means), an object recognition part 13 (acquisition means), and a tactile sensor 3. The tactile sensor 3 includes, for example, a robot control part 15 (control device, acquisition means), a first sensor control part 17-1, a second sensor control part 17-2,..., an nth sensor control part 17-n, a joint control part 19-11, a joint control part 19-12, a joint control part 19-21, a joint control part 19-22,..., a joint control part 19-n1, a joint control part 19-n2, sensors 21-11, sensors 21-12, sensors 21-21, sensors 21-22,..., sensors 21-n1, sensors 21-n2, and a communication part 23.

[0018] Note that the robot 1 is equipped with a power supply unit (not shown) that supplies power to each part. In the following description, when one of the first sensor control unit 17-1, the second sensor control unit 17-2, …, the nth sensor control unit 17-n is not specified, it is referred to as the "sensor control unit 17". Also, when one of the joint control units 19-11, joint control unit 19-12, joint control unit 19-21, joint control unit 19-22, …, joint control unit 19-n1, joint control unit 19-n2 is not specified, it is referred to as the "joint control unit 19".

[0019] The imaging device 11 includes, for example, an RGB camera and a depth sensor.

[0020] Based on the captured image and the detection result detected by the sensor, the object recognition unit 13 detects object information such as the three-dimensional position, size, and shape of the target object in the captured image by a well-known method. The object recognition unit 13 refers to a pattern matching model or the like stored in its own memory, and performs image processing (edge detection, binarization processing, feature quantity extraction, image enhancement processing, image extraction, pattern matching processing, etc.) on the captured image to estimate the object name. Note that when a plurality of objects are detected from the captured image, the object recognition unit 13 detects object information for each object.

[0021] Based on the visual information recognized by the object recognition unit 13 and the sensitivity table stored in its own unit, the robot control unit 15 determines whether to switch the sensitivity of the sensor 21. The sensitivity table will be described later. The robot control unit 15 generates a sensitivity adjustment command based on the determination result, and outputs the generated sensitivity adjustment command to the first sensor control unit 17-1. Note that the sensitivity adjustment command may include information on the target that identifies the sensor 21 to be controlled.

[0022] The sensor control unit 17 acquires the sensitivity adjustment command. The sensor control unit 17 acquires the detection data detected by the sensor that has been converted into digital data by the joint control unit. The sensor control unit 17 outputs the detection data to the robot control unit 15.

[0023] The first sensor control unit 17-1 outputs the sensitivity adjustment command output by the robot control unit 15 to the joint control unit 19-11, the joint control unit 19-12, and the second sensor control unit 17-2. The first sensor control unit 17-1 acquires the detection data output by each of the joint control unit 19-11 and the joint control unit 19-12, and outputs the acquired detection data to the second sensor control unit 17-2.

[0024] 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 unit 19-21, the joint control unit 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 each of the joint control unit 19-21 and the joint control unit 19-22, 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.

[0025] The n-th 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 unit 19-n1 and the joint control unit 19-n2. The n-th sensor control unit 17-n acquires the detection data output by each of the joint control unit 19-n1 and the joint control unit 19-n2, 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.

[0026] The joint control unit 19 switches the sensitivity of the sensor 21 according to the sensitivity adjustment command. Note that the configuration example and operation of the joint control unit 19 will be described later.

[0027] The sensor 21 is a tactile sensor and detects the force on an object (the pressure by a finger). Note that the sensor 21 may be provided in the joint control unit 19.

[0028] [Configuration Example of Joint Control Unit 19] Next, a configuration example of the joint control unit 19 will be described. FIG. 4 is a diagram showing a configuration example of the joint control unit according to the present embodiment. As shown in FIG. 4, the joint control unit 19 includes, for example, a variable resistor R1 (reference voltage variable resistor), a resistor R2, a resistor R3, a variable resistor R4 (first gain resistor, gain variable resistor), a variable resistor R5 (second gain resistor, gain variable resistor), a DAC (digital-analog converter) 191, a comparison amplifier circuit 192, and an ADC 193. Note that the configuration example of the joint control unit 19 shown in FIG. 4 is an example and is not limited thereto.

[0029] One end of the sensor 21 is connected to the voltage Vdd, and the other end is connected to one end of the variable resistor R1 and one end of the resistor R3. The other end of the variable resistor R1 is grounded, and the resistance value r ref is varied by adjustment data indicating an adjustment amount based on the sensitivity adjustment command. The DAC 191 has adjustment data input to its input terminal, and its output terminal is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the negative input terminal of the comparison amplifier circuit 192 and one end of the variable resistor R4. The other end of the resistor R3 is connected to the positive input terminal of the comparison amplifier circuit 192 and one end of the variable resistor R5. The other end of the variable resistor R4 is connected to the output terminal of the comparison amplifier circuit 192 and the input terminal of the ADC, and the resistance value r g2_1 is varied by the adjustment data. The other end of the variable resistor R5 is grounded, and the resistance value r g2_2 is varied by the adjustment data.

[0030] The variable resistor R1, the variable resistor R4, and the variable resistor R5 are, for example, digital potentiometers. Also, the adjustment data is transmitted by the joint control unit 19 to each part by, for example, serial communication (I2C).

[0031] Here, the resistance value of the sensor 21 is r s , the resistance value of the variable resistor R1 is rref, the resistance value of the resistor R2 is Rg1, the resistance value of the resistor R3 is Rg1, the resistance value of the variable resistor R4 is r g2_1 (= r g2 ), and the resistance value of the variable resistor R5 is r g2_2 (= rg2 ) and set the output voltage of DAC191 as Vref. The output voltage Vout of sensor 21 is expressed by the following formula (1).

[0032]

Equation

[0033] Also, the input voltage Vadc to ADC193 is expressed by the following formula (1).

[0034]

Equation

[0035] [Example of sensitivity table] Next, an example of the sensitivity table will be described. FIG. 5 is a diagram showing an example of the sensitivity table according to the present embodiment. As shown in FIG. 5, in the sensitivity table, for example, an object name is associated with a sensitivity mode, a resistance value of a first gain resistor, a resistance value of a second gain resistor, and a resistance value of a reference voltage variable resistor. Note that the sensitivity table shown in FIG. 5 is just an example and is not limited thereto.

[0036] [Example of processing procedure] Next, an example of the processing procedure of robot 1 will be described. FIG. 6 is a flowchart of an example of the processing procedure of the robot according to the present embodiment.

[0037] (Step S1) The object recognition unit 13 performs image processing on the image captured by the imaging device 11 by a well-known method to recognize the object, such as the position of the object, the size of the object, and the object name.

[0038] (Step S2) The robot control unit 15 selects a sensitivity mode based on the result recognized by the object recognition unit 13.

[0039] (Step S3) The robot control unit 15 determines whether the selected sensitivity mode is different from the initial mode. ~ If it is determined that the selected sensitivity mode is different from the initial mode (Step S3; YES), the process proceeds to the process of Step S4. ~ If it is determined that the selected sensitivity mode is not different from the initial mode (Step S3; NO), the process proceeds to the process of Step S5.

[0040] (Step S4) The robot control unit 15 switches to the selected sensitivity mode.

[0041] (Step S5) The robot control unit 15 controls the robot hand 31 to approach the object (object approach).

[0042] (Step S6) The robot control unit 15 controls the robot hand 31 to pick up the object.

[0043] (Step S7) The robot control unit 15 controls the robot hand 31 to perform a predetermined operation (for example, in-hand manipulation).

[0044] (Step S8) The robot control unit 15 controls the robot hand 31 to place (release, put) the object.

[0045] (Step S9) The robot control unit 15 determines whether the sensitivity mode has been switched. ~ If it is determined that the sensitivity mode has been switched (Step S9; YES), the process proceeds to the process of Step S10. ~ If it is determined that the sensitivity mode has not been switched (Step S9; NO), the process ends.

[0046] (Step S10) The robot control unit 15 switches the sensitivity mode and returns to the initial mode.

[0047] [Example of Processing at Sensitivity Switching] Next, an example of sensitivity switching will be described. FIG. 7 is a diagram showing examples of the high-sensitivity mode and the wide-area mode according to the present embodiment. Graph g101 represents the relationship between the force and the input voltage to ADC193 in the high-sensitivity mode. Graph g102 represents the relationship between the force and the input voltage to ADC193 in the wide-area mode. In graphs g101 and g102, the horizontal axis represents the force, and the vertical axis represents the voltage value. Note that the resolution of ADC193 is assumed to be 10 bits.

[0048] As shown in graph g101, in the high-sensitivity mode, for example, it is used when the force is less than a predetermined value. Then, by adjusting 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, for example, 10 bits are applied to the threshold voltages Vth to V1. Alternatively, in the high-sensitivity mode, for example, 10 bits are applied to the voltage values Vth to V2. Note that the threshold voltage Vth is variable. Thus, even in the high-sensitivity mode, there may be a plurality of combinations of 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.

[0049] As shown in graph g102, in the wide-area mode, for example, it is used when the force is greater than or equal to a predetermined value. Then, by adjusting 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, for example, 10 bits are applied to the threshold voltages Vth to V11. Alternatively, in the wide-area mode, for example, 10 bits are applied to the voltage values Vth to V13. Note that the threshold voltage Vth is variable. Thus, even in the wide-area mode, there may be a plurality of combinations of 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.

[0050] As shown in graphs g101 and g102, in the high-sensitivity mode, the range of the input voltage to ADC193 is wider than that in the wide-area mode, and the range of the force f1 is narrower than that in the wide-area mode. As shown in graphs g101 and g102, in the wide-area mode, the range of the force f 11 is wider than that in the high-sensitivity mode, and the range of the input voltage to ADC193 is narrower than that in the high-sensitivity mode. Note that each voltage, threshold voltage, and force range shown in FIG. 7 is an example and is not limited thereto.

[0051] Next, an example of the gain switching procedure in the high-sensitivity mode will be described. FIG. 8 is a diagram showing an example of the gain switching procedure in the high-sensitivity mode according to the present embodiment. In graphs g151 and g152, the horizontal axis represents force and the vertical axis represents voltage value. Graph g151 is the graph before mode switching. Assuming that the relationship between voltage V and force f is V = g(f) and the threshold voltage Vth is 0 (V). Here, assume that the detection band required for detection by the sensor 21 is f1.

[0052] Graph g152 is the graph after mode switching. In the high-sensitivity mode, when the gain is, for example, twice, the relationship between voltage V and force f is V = gain×(g(f) - Vth) = 2×g(f).

[0053] Next, an example of the gain switching procedure in the wide-area mode will be described. FIG. 9 is a diagram showing an example of the gain switching procedure in the wide-area mode according to the present embodiment. In graphs g171, g172, and g173, the horizontal axis represents force and the vertical axis represents voltage value. Graph g171 is the graph before mode switching. Assuming that the relationship between voltage V and force f is V = g(f). Here, assume that the detection band required for detection by the sensor 21 is f1 to f2.

[0054] Graph g172 is the graph after mode switching. In the wide-area mode, when the gain is, for example, five times, the relationship between voltage V and force f is V = gain×(g(f) - Vth) = 5×(g(f) - Vth).

[0055] Here, adjustment data for 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 is input, for example, as serial data. Therefore, there may be a time difference in the timing when 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 change. Also, due to current changes in the analog circuit, chattering of the switch operation of the switching means, etc., even if the same force f1 is applied before and after gain switching, the value of the voltage V that is the output may be different. As a result, when the analog circuit is switched, the voltage may become instantaneously unstable. Because of this, there is a possibility that the gripping control (force control) of the object may malfunction.

[0056] FIG. 10 is a diagram showing an operation example at the time of gain switching. Graph g201 shows the time difference and unstable region due to communication at the time of gain switching. The horizontal axis is time and the vertical axis is voltage. At time t1, the threshold voltage Vth is switched, and the period T2 from time t1 to t2 is the operation unstable region. At time t3, the resistance value of the first gain resistor is switched, and the period T3 from time t3 to t4 is the operation unstable region. At time t5, the resistance value of the second gain resistor is switched, and the period T4 from time t4 to t6 is the operation unstable region. Also, the period T1 from time t1 to t7 indicates the time difference in the setting by communication. As in graph g201, due to this gain switching, although it is originally desired to switch from voltage value Vb to Va, it changes stepwise and includes an unstable period.

[0057] Graph g202 shows the relationship between time and force when gain switching as in graph 201 is performed. The horizontal axis is time and the vertical axis is force. As in graph g202, the applied force value is constant at f1, but the force during the gain switching period T1 does not become constant. Therefore, the data during this period T1 may malfunction if used for control data and thus cannot be used. Note that the force conversion formula for the period from time t1 to t7 is f = g -1 (V), and the force conversion formula after time t7 is f = g -1( V / G + Vth).

[0058] In contrast, in the present embodiment, as shown in graph g173, during the period of the time difference in communication settings (switching period), the force f1 before the start of switching is maintained. Graph g173 is a graph showing the relationship between the force and time when the gain is switched in the present embodiment. As a result, the force conversion formula up to time t1 is f = g -1 is represented by (V), the force conversion formula during the period from time t1 to t7 is represented by f = f1, and the force conversion formula after time t7 is f = g -1( V / G + Vth).

[0059] By such processing, according to the present embodiment, it is possible to prevent the influence of the time difference due to communication at the time of gain switching, the influence of switching chatter, the influence of current change by the analog circuit, etc. Note that the robot control unit 15 can dynamically change the gain switching and threshold switching by communication during the operation of the robot 1.

[0060] [Modification Example] In the above-described example, two examples of the gain mode, namely the high-sensitivity mode and the wide-area mode, have been described. However, the gain mode may be two or more. In this case, as shown in FIG. 11, several ranges may be provided for the force f.

[0061] FIG. 11 is a diagram showing an example of the gain switching range in the modification example. In FIG. 11, the horizontal axis represents the force and the vertical axis represents the input voltage to the ADC. Mode I is a mode that covers the range of forces f0 to f6. Modes II and III are modes that cover the range of forces f0 to f6 in two modes. Modes IV to VII are modes that cover the range of forces f0 to f6 in four modes. Mode VIII is a mode that covers a part of the range of forces f0 to f6, namely f2 to f5. Mode IX is a mode that covers a part of the range of forces f0 to f6, namely f1 to f4.

[0062] The robot control unit 15 switches the plurality of modes shown in FIG. 11 according to the recognized object as shown in FIG. 12, for example. FIG. 12 is a diagram showing an example of the correspondence between the switching mode, the load range, the resolution, the object, the grasped object, and the operation according to the present embodiment. Note that the robot control unit 15 stores the relationship shown in FIG. 12. Alternatively, the robot control unit 15 may acquire and store it via a network or the like.

[0063] As shown in FIG. 12, for example, in Mode I, the load range is "low to high", the resolution is "low", the object is "heavy objects. Those that can be handled roughly. When the load changes greatly", etc., the grasped object is "2L plastic bottle, rice bag", etc., and the operation is "opening the lid of a bottle, pouring water from a 2L plastic bottle", etc.

[0064] Also, for example, in Mode V, the load range is "low to medium", the resolution is "high", the object is "those with a slightly low load and requiring delicate handling. Precision instruments", etc., and the grasped object is "egg, smartphone, remote control", etc.

[0065] Also, for example, in Mode IX, the load range is "medium", the resolution is "medium", the object is "in the medium load region when the load changes to some extent", etc., and the operation is "gently stroking a child", etc.

[0066] FIG. 13 is a diagram showing the relationship between the load range and an example of the force range according to the present embodiment. As shown in FIG. 13, the force range of the load range "low" is, for example, "0.01 to 0.5 (N), 1 to 50 (g)". The force range of the load range "low to medium" is, for example, "0.5 to 0.2 (N), 50 to 200 (g)". The force range of the load range "medium to high" is, for example, "2 to 10 (N), 200 (g) to 10 (kg)". The force range of the load range "high" is, for example, "10 (N) or more, 10 (kg) or more".

[0067] Note that the switching modes shown in FIGS. 11 and 12 are merely examples and are not limited thereto. Also, the load range, resolution, target, gripped object, and operations of the switching mode shown in FIG. 12 are merely examples and are not limited thereto. The example of the force range of the load range shown in FIG. 13 is also merely an example and is not limited thereto. Also, each range may be fixed or variable. When varying the range width, for example, the range may be adjusted based on the detection value of the actually detected sensor 21.

[0068] Note that the robot control unit 15 may change the range by predicting future states and operation changes. For example, when gripping a cup and pouring water into or out of the cup, the robot control unit 15 may make predictions based on the result of environmental recognition based on visual information.

[0069] As described above, in the present embodiment, the sensitivity of the ADC 193 to which the output of the sensor 21 is input is switched according to the object recognized based on the visual information. Also, in the present embodiment, the switching of the sensitivity mode is performed by switching the gain and the reference voltage. Also, in the present embodiment, the switching timing period by communication at the time of mode switching is kept constant with the force.

[0070] Accordingly, according to the present embodiment, a force resolution corresponding to the object to be handled can be obtained, and both delicate work and strong work can be realized in the same system. Also, according to the present embodiment, malfunction due to variations such as switching timing by communication at the time of switching can be prevented.

[0071] <Second Embodiment> In the present embodiment, the sensitivity of the tactile sensor is switched based on visual information and tactile information.

[0072] (Example of Robot Configuration) FIG. 14 is a diagram showing an example of the configuration of a robot including the sensor according to the present embodiment. As shown in FIG. 14, the robot 1A includes a photographing device 11 (acquisition means), an object recognition unit 13 (acquisition means), and a tactile sensor 3A. The tactile sensor 3A includes, for example, a robot control unit 15A (control device, acquisition means), a first sensor control unit 17A-1, a second sensor control unit 17A-2, …, an n-th 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, sensors 21-11, sensors 21-12, sensors 21-21, sensors 21-22, …, sensors 21-n1, sensors 21-n2, and a communication unit 23.

[0073] Note that the robot 1A includes a power supply unit (not shown) that supplies power to each unit. In the following description, when one of the first sensor control unit 17A-1, the second sensor control unit 17A-2, …, the n-th sensor control unit 17A-n is not specified, it is referred to as the "sensor control unit 17A". Also, when one of the joint control unit 19A-11, the joint control unit 19A-12, the joint control unit 19A-21, the joint control unit 19A-22, …, the joint control unit 19A-n1, the joint control unit 19A-n2 is not specified, it is referred to as the "joint control unit 19A".

[0074] The joint control unit 19A acquires the tactile information detected by the sensor 21 when an object is grasped, and outputs the acquired tactile information to the sensor control unit 17A. Note that an example of the circuit configuration of the joint control unit 19A is the same as that of FIG. 4 in the first embodiment, for example.

[0075] The sensor control unit 17A outputs the acquired tactile information to the robot control unit 15A.

[0076] The robot control unit 15A first switches the sensitivity mode based on the visual information in the same manner as in the first embodiment. Next, the robot control unit 15A determines whether to adjust the sensitivity based on the tactile information when actually grasping, and adjusts the sensitivity based on the determination result.

[0077] [Example of processing procedure] Next, an example of the processing procedure of the robot 1A will be described. FIG. 15 is a flowchart of an example of the processing procedure of the robot according to the present embodiment.

[0078] (Steps S1 to S6) Robot 1A performs the processes of Steps S1 to S5.

[0079] (Step S101) The robot control unit 15A detects the weight of the grasped object by a well-known method based on the tactile information when actually grasping.

[0080] (Step S102) The robot control unit 15A determines whether the weight is as expected in the sensitivity mode switched based on the visual information (for example, refer to FIG. 13). When the robot control unit 15A determines that the weight is as expected (Step S102; YES), it performs the processes of Steps S7 to S10. When the robot control unit 15A determines that the weight is not as expected (Step S102; NO), it proceeds to the process of Step S103.

[0081] (Step S103) The robot control unit 15A determines whether the weight of the grasped object is lighter than expected. When the robot control unit 15A determines that the weight of the grasped object is lighter than expected (Step S103; YES), it proceeds to the process of Step S104. When the robot control unit 15A determines that the weight of the grasped object is not lighter (heavier) than expected (Step S103; NO), it proceeds to the process of Step S105.

[0082] (Step S104) The robot control unit 15A increases the sensitivity for the switched sensitivity mode. After the process, the robot control unit 15A returns to the process of Step S6.

[0083] (Step S105) The robot control unit 15A decreases the sensitivity for the switched sensitivity mode. After the process, the robot control unit 15A returns to the process of Step S6.

[0084] Note that the processing procedure shown in FIG. 15 is just an example and is not limited thereto. For example, in step S103, the robot control unit 15A may determine whether the weight is heavier than expected. In this case, the robot control unit 15A may lower the sensitivity when it is heavier than expected and increase the sensitivity when it is not heavier than expected. Alternatively, the robot control unit 15A may increase or decrease the sensitivity by transitioning the sensitivity mode from, for example, mode II in FIG. 11 to mode IV or VI. Or, the robot control unit 15A may increase or decrease the sensitivity by finely adjusting the sensitivity mode with respect to, for example, mode II in FIG. 11.

[0085] Note that also in this embodiment, similar to the first embodiment, the switching of the sensitivity mode is performed by gain switching and reference voltage switching. Also in this embodiment, during the switching timing period by communication at the time of mode switching, it is kept constant with the force.

[0086] Accordingly, according to this embodiment, since the sensitivity mode corresponding to the contact object is set based on the visual information and the tactile information, a force resolution corresponding to the object to be handled with higher accuracy can be obtained, and both delicate work and powerful work can be realized in the same system.

[0087] Note that the robot in each of the above-described embodiments and modified examples only needs to be equipped with a robot hand, and may be a bipedal walking robot, a working robot, a reception robot, a care robot, or the like. Also, the robot hand of the robot in each of the above-described embodiments and modified examples only needs to be equipped with at least two or more finger parts.

[0088] In addition, in each of the above-described embodiments and modifications, the operation control of one robot hand has been described as an example, but there may be two or more robot hands. In this case, the robot control unit 15 (or 15A) may switch the sensitivity mode of each robot hand based on the visual information. In this case, the robot control unit 15 (or 15A) may, for example, switch the sensitivity modes for the first robot hand and the second robot hand to the same sensitivity mode, or may switch them to different sensitivity modes.

[0089] Furthermore, the robot control unit 15A may adjust the sensitivity modes for the first robot hand and the second robot hand in the same way or differently based on the tactile information actually grasped.

[0090] Also, the robot control unit 15 (or 15A) may switch the sensitivity mode based on the tactile information. Then, the robot control unit 15 (or 15A) may adjust the sensitivity mode switched based on the tactile information based on the visual information.

[0091] Note that a program for realizing all or part of the functions of the robot 1 (or 1A) in the present invention may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to perform all or part of the processing performed by the robot 1 (or 1A). Here, the "computer system" shall include hardware such as an OS and peripheral devices. Further, the "computer system" shall also include a system constructed on a local network, a system constructed on the cloud, etc. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, etc., and a storage device such as a hard disk incorporated in a computer system. Furthermore, the "computer-readable recording medium" also includes a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line, and that holds the program for a certain period of time.

[0092] Also, the above program may 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 by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication wire) such as a telephone line. Further, the above program may be for realizing a part of the functions described above. Furthermore, it may be a so-called difference file (difference program) that can realize the functions described above in combination with a program already recorded in a computer system.

[0093] As described above, the embodiments for implementing the present invention have been described using the embodiments, but the present invention is not limited to such embodiments, and various modifications and substitutions can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0094] 1, 1A... robot, 3, 3A... tactile sensor, 31... robot hand, 33... gripping part, 331... finger part, 331a... thumb, 331b... index finger, 331c... middle finger, 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, 11... imaging device, 13... object recognition unit, 15, 15A... robot control unit, 17... sensor control unit, 17 - 1... first sensor control unit, 17 - 2... second sensor control unit, ···, 17 - n... nth sensor control unit, 19, 19 - 11, 19 - 12, 19 - 21, 19 - 22, ···, 19 - n1, 19 - n2... joint control unit, 23... communication unit, 192... comparison and amplification circuit, 193... ADC

Claims

【Claim 1】 A comparison and amplification circuit that compares and amplifies the voltage value output by a tactile sensor attached to the hand part of a robot and a reference voltage value; A gain variable resistor that varies the gain of the comparison and amplification circuit in response to an instruction to switch the sensitivity mode of the tactile sensor; A reference voltage variable resistor that varies the voltage value output by the tactile sensor in response to an instruction to switch the sensitivity mode of the tactile sensor; An analog-to-digital converter that converts the analog value output by the comparison and amplification circuit into a digital value; A sensitivity switching circuit comprising the above.

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