JP4023614B2 - Gripping device, gripping control method, gripping control program, and recording medium - Google Patents

Description

  The present invention relates to a gripping device such as an articulated manipulator used for a robot or a gripper, a grip control method, a grip control program, and a recording medium on which the grip control program is recorded.

  In recent years, various studies have been carried out in the field of robotics. As one of them, a new technology for mounting on a humanoid robot is being developed for a robot hand that has been developed as a gripping device such as an industrial manipulator. In this case, in order for a robot to work on behalf of a person, gripping an object with a hand having a plurality of fingers that can be independently driven is an indispensable technique. In such a technique in which a robot grips an object like a person, it is necessary to perform fine grip control while accurately detecting the grip state. For this reason, a plurality of contact sensors whose resistance values change according to the contact pressure are arranged on the finger part of the hand that is gripped by the robot, and while detecting the contact pressure of the contact sensor and using the detected contact pressure, A technology for feedback control of the finger of the hand has been developed.

For example, when an object is gripped by a plurality of fingers equipped with a contact sensor, the object is controlled by controlling the finger using the minimum value among the signal values from each contact sensor as a reference value at the time of gripping the object. There has been proposed a technique that enables stable gripping (see, for example, Patent Document 1). In addition, when grasping an object with a plurality of fingers equipped with a contact sensor, the size of the object is grasped from the opening amount between the fingers, and the size of the contact area when grasping with a predetermined force is detected. There has also been proposed one that performs grip control by calculating the degree of flexibility of an object from the ratio of the size of the object and the size of the touch area (see, for example, Patent Document 2).
JP-A-5-297918 JP-A-8-323678

  By the way, in the above-described gripping device, in order to perform feedback control of the finger of the hand using the contact pressure detected by the contact sensor disposed on the finger part of the hand, the gripped object contacts any part of the fingertip. It is important to detect whether it is present. For this purpose, the higher the area resolution of the contact sensor in the area where the contact state is to be detected, the better. However, in order to increase the area resolution, the number of contact sensors in the area to be detected must be increased. In that case, collecting the contact pressures of all the contact sensors and extracting the information necessary for the grip control from them collects a burden on the information processing system, resulting in a problem of inefficiency. In addition, as the number of contact sensors increases, it takes time to collect the contact pressure of the contact sensors. Therefore, there is a problem that the reliability of data used for grip control is lowered.

  In this regard, in the method disclosed in Patent Document 1, it is necessary to check the signal values of all the contact sensors in order to know the minimum value from the signal values from the respective contact sensors detected when the object is gripped. It is difficult to solve the above problem by this method. Similarly, in the method of Patent Document 2 described above, in order to know the size of the contact area when an object is grasped with a predetermined force, the values of all the contact sensors provided on the plurality of fingers are set. It is necessary to check, and even with this method, it is difficult to solve the above problem.

  In the gripping device as described above, the contact pressure of the contact sensor needs to be collected from the moment when the finger part of the hand grips the gripping object. However, conventionally, a wasteful process of always collecting the contact pressure of the contact sensor is performed even before the finger part of the hand grips the object to be gripped. There was a problem that became heavy.

  Therefore, the present invention has been made to solve the above-described problems, and does not reduce the area resolution in the detection of the contact pressure by the contact sensor, that is, the contact sensor necessary for maintaining the high area resolution. By efficiently collecting contact pressure of the contact sensor without reducing the number of use, reducing the burden on the information processing system, and shortening the contact pressure collection time to obtain highly reliable data, An object of the present invention is to provide a gripping device, a gripping control method, a gripping control program, and a recording medium on which the gripping control program is recorded that enables stable gripping control.

  A gripping device of the present invention made to solve the above-described problem includes a plurality of fingers that can be driven independently, a multi-finger hand-type gripping means that grips a gripping object using the fingers, and the fingers. A plurality of contact sensors each of which is provided with a plurality of driving means and a gripping object that is provided on the finger and that is in contact with the gripping object and that is provided with a sensor address; An initial sensor list in which the sensor address of the selected contact sensor selected from among them is registered in advance; sensor list setting means for initially setting the sensor address registered in the initial sensor list to the sensor list; and processing for updating the sensor list A sensor list updating means for performing all of the sensor addresses set in the sensor list every time the initial setting or the updating process is performed. Then, sensor information collecting means for sequentially collecting contact pressure and recording it in the sensor list, drive control means for calculating drive control information for the finger based on the contact pressure and providing the drive means, It is characterized by having.

  In the gripping device, the sensor list setting unit determines whether or not the contact pressure exceeds a predetermined threshold every time the contact pressure is sequentially collected by the sensor information collection unit. The sensor address of the over-threshold contact sensor exceeding the threshold value and the sensor address of the contact sensor in a specific positional relationship with the over-threshold contact sensor are set in the sensor addition list, and the sensor list update means is the sensor information collection means After the collection of contact pressures for the contact sensors of all sensor addresses in the sensor list according to the above, the sensor list update process may be performed based on the information of the sensor addition list and the initial sensor list.

  In the above gripping device, the contact sensors in the specific positional relationship may be all sensors separated by one unit distance from the over-threshold contact sensor. In addition, as the update process, only the sensor address set in the sensor addition list and the sensor address registered in the initial sensor list may be set in the sensor list.

  In the above gripping device, the contact pressure detected by a plurality of the contact sensors or the contact sensors of the sensor addresses registered in the initial sensor list is monitored, and when any one of the contact pressures changes first. The sensor list setting unit may include a contact determination unit that instructs the sensor list to initially set a sensor address registered in the initial sensor list. Alternatively, the driving load of the driving means for driving the finger is monitored, and when the driving load exceeds a predetermined value, the sensor address registered in the initial sensor list is set to the sensor list setting means. You may make it provide the contact judgment means to instruct | indicate the initialization to a sensor list.

  In the gripping device, the sensor information collecting unit may contact the sensor sensor when all the sensor addresses of the sensor list updated by the sensor list updating unit are the same as the initial sensor list. The pressure collection may be stopped.

  The gripping device includes a plurality of initial sensor lists according to the type of the gripping object, and selects one of the initial sensor lists for initial setting of the sensor list based on the provided selection command. You may make it provide the initial sensor list selection means to do.

  The grip control method of the present invention comprises a plurality of fingers that can be driven independently, a multi-finger hand-type gripping means for gripping a gripping object using the fingers, a drive means for driving the fingers, and the fingers A plurality of contact sensors that detect a contact pressure with a gripping object that is in contact with the gripping object and that are each assigned a sensor address, and a selected contact sensor selected from the plurality of contact sensors. A gripping control method in a gripping apparatus, comprising: an initial sensor list in which sensor addresses are registered in advance; and a driving control unit that calculates finger driving control information based on the contact pressure and provides the driving unit with the driving control information. A sensor list setting step for initially setting a sensor address registered in the initial sensor list in the sensor list; an update processing step for performing update processing of the sensor list; Each time the initial setting or the updating process is performed in the sensor list setting step or the update processing step, the contact pressure is sequentially collected for the contact sensors of all the sensor addresses set in the sensor list, and the sensor list is collected. The sensor information collecting step to be recorded and the contact pressure collection sequentially performed by the sensor information collecting step determine whether or not the contact pressure exceeds a predetermined threshold value. A sensor addition list setting step for setting in the sensor addition list the sensor address of the contact sensor and the address of the contact sensor having a specific positional relationship with the threshold excess contact sensor, and the update processing step includes the sensor For contact sensors of all sensor addresses in the sensor list in the information collecting step After collection of the contact pressure ends, it is characterized by performing the updating of the sensor list on the basis of the sensor additional list and information of the initial sensor list.

  In the above grip control method, the sensor addition list setting step may certify all sensors separated by one unit distance from the over-threshold contact sensor as the contact sensors having the specific positional relationship. In the update process step, only the sensor address set in the sensor addition list and the sensor address registered in the initial sensor list may be set in the sensor list as the update process.

  Further, in the above grip control method, when the contact pressure detected by a plurality of the contact sensors or the contact sensors of the sensor addresses registered in the initial sensor list is monitored and any one of the contact pressures is changed for the first time. May be performed before the sensor list setting step. Alternatively, the contact determination step of monitoring the drive load of the drive means for driving the finger and detecting when the drive load exceeds a predetermined value as the contact start time is executed before the execution of the sensor list setting step. You may do it.

  In the above grip control method, when all the sensor addresses of the sensor list updated by the sensor list update step are the same as the initial sensor list, collection of contact pressure from the contact sensor is stopped. The sensor stop step may be executed instead of the sensor information collection step.

  In the grip control method described above, a plurality of initial sensor lists are provided according to the type of the gripping object, and one of the initial sensor lists is used for initial setting of the sensor list based on the provided selection command. The initial sensor list selection step to be selected may be executed before the execution of the contact determination step, if not, or before the execution of the sensor list setting step.

  The grip control program of the present invention is a grip control program that causes a computer to execute each step of any of the grip control methods described above. The grip control program can be recorded on a computer-readable recording medium record.

  In the gripping device of the present invention, as described above, each time the contact pressure is sequentially collected by the sensor information collecting means, the sensor list setting means determines whether or not the contact pressure exceeds a predetermined threshold. In this case, the sensor address of the contact sensor exceeding the threshold value and the sensor address of the contact sensor having a specific positional relationship with the contact sensor exceeding the threshold value are set in the sensor addition list. Then, after the collection of the contact pressures of all the contact sensors in the sensor list by the sensor information collection unit, the sensor list update unit performs the update process of the sensor list based on the information of the sensor addition list and the initial sensor list. In the above gripping device, the contact sensors in the specific positional relationship are all sensors that are one unit distance away from the over-threshold contact sensors, and the sensors set in the sensor addition list as the contents of the update process Only the sensor address set in the address and the initial sensor list can be set in the sensor list.

  Therefore, according to the gripping device of the present invention, it is configured not to collect the contact pressures of all the contact sensors, but to collect only the contact pressures of the selected contact sensors selected in advance from among a plurality of contact sensors. In addition, with the movement of the finger part of the multi-fingered hand-type gripping means that the gripping object comes into contact with, the contact sensor that should collect the contact pressure is changed to only the contact sensor that needs to collect the contact pressure. Since it is constituted so that the contact pressure of the contact sensor can be collected sufficiently and the collection time can be shortened. Therefore, it is possible to efficiently collect the contact pressure of the contact sensor without reducing the area resolution in the detection of the contact pressure by the contact sensor, that is, without reducing the number of contact sensors used to maintain the high area resolution. In addition, the burden on the information processing system is reduced, and the collection time of contact pressure is shortened to obtain highly reliable data, whereby stable gripping control can be performed.

  In the above gripping device, the contact pressure detected by a plurality of contact sensors or the contact sensor of the sensor address set in the initial sensor list is monitored, and when any of the contact pressures is changed for the first time, the sensor is detected. A contact determination means for instructing the list setting means to initially set the sensor address registered in the initial sensor list in the sensor list can be provided. Alternatively, the driving load of the driving means for driving the finger is monitored, and when the driving load exceeds a predetermined value, the sensor address registered in the initial sensor list is initially stored in the sensor list with respect to the sensor list setting means. Contact determination means for giving an instruction to set can be provided. In these cases, the contact pressure of the contact sensor is not collected until just before any of the fingers of the multi-fingered hand-type grasping means contacts the object to be grasped. Collection can be prevented, and the burden on the information processing system in each means of the gripping device can be reduced.

  In the above gripping device, the sensor information collecting unit collects the contact pressure from the contact sensor when all the sensor addresses of the sensor list updated by the sensor list updating unit are the same as the initial sensor list. Since it can stop, the burden of the information processing system in each means of the gripping device can be reduced.

  In the above gripping device, the sensor includes a plurality of initial sensor lists according to the type of the gripping object, and selects one of the initial sensor lists for initial setting of the sensor list based on the provided selection command. Since the list selection means can be provided, the initial setting of the sensor list can be optimized depending on the object to be grasped. Depending on the object to be grasped, the contact pressure collection efficiency of the contact sensor and the means of the grasping device It is possible to reduce the burden on the information processing system and shorten the collection time of contact pressure to the maximum, and to enable stable gripping control.

  Further, by using the grip control method of the present invention or by using the grip control program of the present invention, these grip control methods and grip control programs have the functions corresponding to the respective functions described above. The same effect as that of the gripping device can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

<Embodiment 1>
A gripping device according to Embodiment 1 of the present invention is a hand (gripping device) 1 that is a portion corresponding to a human hand in a humanoid robot 10 as shown in FIG. This hand (gripping device) 1 includes a hand mechanism 1a shown in FIG. 1 (a) having five fingers 1b having two to three joints that can be independently driven (the above-mentioned multi-finger hand-type gripping means). Equivalent). In addition to the hand (gripping device) 1, the humanoid robot 10 includes an arm 2 for moving the hand mechanism 1a to the object to be grasped, a body 3 that supports the arm 2, and a camera 4a in the eye portion. The head 4 is configured.

  FIG. 2 is a functional block diagram of a control system for controlling the humanoid robot 10 having the above configuration. This control system includes a processing unit 11, a control unit 12, a drive unit 13, a recording unit 14, a sensor unit 15, an image input unit 16, and a power supply unit 17. Among them, the processing unit 11, the control unit 12, the recording unit 14, the image input unit 16, and the power supply unit 17 are installed inside the body 3, the head 4, or the like or in a separately provided control casing.

  The processing unit 11 is a part for making an action plan for the entire robot, and receives information from the image input unit 16 and the sensor unit 15 or a command from another processing unit through communication. Processing is performed, and a command for the humanoid robot 10 to act is given to the control unit 12.

  The control unit 12 is a part that performs control for driving the hand (gripping device) 1, arm 2, body 3, head 4, etc., and is provided for each component of the humanoid robot 10. It is good also as one control part 12 collectively. The control unit 12 generates a control signal for causing each component of the humanoid robot 10 to perform a predetermined operation in response to a command from the processing unit 11 and outputs the control signal to the drive unit 13.

  The drive unit 13 is a part that actually operates the humanoid robot 10. The drive unit 13 is provided for each constituent part of the humanoid robot 10 and is built in the constituent part, and is responsible for driving the constituent part. The drive unit 13 includes a motor or the like for driving the components, and drives the motor or the like using electric power supplied from the power supply unit 17 based on a control signal from the control unit 12. The driving parts such as the joints in the constituent parts of the humanoid robot 10 may be directly driven by a motor, or may be indirectly driven by a motor using a cam or gear. The drive unit 13 also includes a portion in charge of the hand (gripping device) 1 (corresponding to the drive means described above).

  The recording unit 14 is a part that records parameters for driving the humanoid robot 10 and temporary information. The processing unit 11, the control unit 12, and the recording unit 14 are configured by a circuit board on which a chip and a memory such as a RISC processor (microcomputer) and FPGA are mounted, but depending on the scale of processing, the processing chip 1. Therefore, the processing of the processing unit 11, the control unit 12, and the recording unit 14 may be performed.

  The sensor unit 15 includes a plurality of contact sensors 5 provided on the side (palm side) of gripping an object to be gripped on the surface of the finger 1b of the hand mechanism 1a shown in FIG. The image input unit 16 is connected to the camera 4a provided in the head 4 of the humanoid robot 10, and performs an input process on an image captured by the camera 4a. The power supply unit 17 is for supplying power to the above-described units, and an external power supply or a battery is used.

  The hand (gripping device) 1 according to the first embodiment of the present invention is a part of the humanoid robot 10 as described above. Therefore, the control for driving the hand mechanism 1a is performed mainly on the processing unit 11, the control unit 12, the driving unit 13 built in the hand mechanism 1a, the recording unit 14, and the finger 1b of the hand mechanism 1a in the above control system. This is performed using a sensor unit 15 including a plurality of contact sensors 5 provided. Next, a system configuration for controlling the hand (gripping device) 1 that uses these parts will be described.

  FIG. 3 is a functional block diagram showing a system configuration of a part of the humanoid robot 10 that mainly controls the hand 1. As described above, the control system includes the processing unit 11, the control unit 12, the recording unit 14, the driving unit 13 (not shown) built in the hand mechanism 1a (corresponding to the driving unit described above), and the hand mechanism 1a. The plurality of contact sensors 5 provided on the finger 1b. The control unit 12 includes a sensor information collection unit 12a (corresponding to the above-described sensor information collection unit), a grip control unit 12b (corresponding to the above-described drive control unit), and a sensor list setting unit 12c (corresponding to the above-described sensor list setting unit). ) And a sensor list update unit 12d (corresponding to the above-described sensor list update unit), and the recording unit 14 includes a sensor list 14a, an initial sensor list 14b, and a sensor addition list 14c.

  The contact sensor 5 has a function of detecting a contact pressure when it comes into contact with a grasped object during grasping. Each contact sensor 5 is given a sensor address, and (number) attached to the contact sensor 5 in FIG. 3 represents this sensor address. The contact sensor 5 includes a circuit as shown in FIG. 4, and the internal resistance of the contact sensor 5 decreases as the contact pressure increases. Therefore, the output voltage increases as the contact pressure increases. In FIG. 4, Vref represents a reference voltage.

  The processing unit 11 provides the control unit 12 with the grip command and the position of the grip target. The grip control unit 12b refers to the information in the recording unit 14, and performs control for gripping such as driving of the finger 1b by using the grip command from the processing unit 11 and the position data of the grip target. The sensor list setting unit 12c performs initial setting of the sensor list 14a using the initial sensor list 14b and performs accompanying control. The sensor list update unit 12d uses the initial sensor list 14b and the sensor addition list 14c provided in the recording unit 14 to update the sensor list 14a that is also provided in the recording unit 14. The sensor information collection unit 12a collects the contact pressure of the contact sensor 5 based on the sensor list 14a and records it in the sensor list 14a. That is, in the sensor list 14a, the sensor address of the contact sensor 5 to be collected and the contact pressure of the contact sensor of this sensor address are recorded corresponding to the sensor address. The initial sensor list 14b is used to initialize the sensor list 14a, and sensor addresses of selected contact sensors selected from all the contact sensors 5 are registered in advance. The sensor addition list 14c is used for setting the sensor address of the contact sensor 5 to be added used for updating the sensor list 14a.

  Next, the operation of the hand (grip device) 1 will be described with reference to FIG. First, the sensor list setting unit 12c sets an information collection mode, which is a mode for collecting information necessary for the operation of the hand (gripping device) 1, and performs initial setting of the sensor list 14a (S1). In this initial setting, the sensor address of the selected contact sensor registered in advance in the initial sensor list 14b is set in the sensor list 14a, and the sensor addition list 14c is cleared (S2).

  Next, the sensor collection unit 12a acquires the contact pressure of the contact sensor 5 of the first sensor address registered in the sensor list 14a (hereinafter, the contact pressure of the contact sensor 5 is referred to as a sensor value), and the sensor list 14a (S3). As described above, since the output voltage as the sensor value increases as the contact pressure increases as described above, the output of the contact sensor 5 that is in contact is higher than the output of the contact sensor 5 that is not in contact. Is obtained. Therefore, the sensor list setting unit 12c determines whether or not the obtained sensor value is equal to or greater than a contact parameter Ptouch value (hereinafter referred to as a threshold value) registered in advance in the recording unit (S4). If so, the sensor address of a specific contact sensor 5 is set in the sensor addition list 14c (S5). This setting is called addition of a contact sensor. The addition of the contact sensor is performed by using the sensor address of the over-threshold contact sensor that is the contact sensor 5 whose sensor value is equal to or greater than the threshold value, and the sensor address of the contact sensor 5 in a specific positional relationship with the over-threshold contact sensor. This is done by setting in the additional list 14c. The contact sensors 5 having a specific positional relationship with the over-threshold contact sensors are all contact sensors 5 that are one unit distance away from the contact sensors 5 that are over-threshold contact sensors. For example, when the plurality of contact sensors 5 are continuously arranged in a planar shape, the term “one unit distance away” refers to the contact sensors 5 arranged adjacent to the periphery of the contact sensors 5. 2 units away means the contact sensor 5 arranged adjacent to the outer periphery of the contact sensor 5 arranged adjacent to the periphery of the contact sensor 5. When the shape of the contact sensor 5 is a square, there are a total of eight contact sensors 5 separated by one unit distance in the vertical, horizontal, and diagonal directions around the contact sensor 5. If the sensor value does not exceed the threshold value in S4, the contact sensor is not added. In the above description, the value (threshold value) of the contact parameter Ptouch is determined by experimentally or theoretically obtaining the output of the contact sensor 5 in a state where it can be said that the contact is reliably performed.

  Next, the sensor list setting unit 12c determines whether or not there is a contact sensor 5 for which sensor values have not been collected (S6). If there is, the sensor value of the contact sensor 5 at that sensor address is collected. (S7), the processing of S4 to S6 is performed. When the collection of the sensor values of the contact sensors 5 of all the sensor addresses set in the sensor list 14a in S6 is completed, the sensor list update unit 12d uses the initial sensor list 14b and the sensor addition list 14c, The sensor list 14a is updated (S8). This update is performed by setting all sensor addresses registered in the initial sensor list 14b and all sensor addresses added to the sensor addition list 14c in the sensor list 14a.

  Then, the sensor list setting unit 12c determines whether or not all the sensor addresses in the updated sensor list 14a are the same as the initial sensor list 14b (S9). Since the sensor address is added to the sensor addition list 14c, the finger 1b of the hand mechanism 1a is in contact with the object to be grasped, and based on the updated sensor list 14a, S4 to S8. Processing is performed.

  On the other hand, when the updated sensor list 14a is the same as the initial sensor list 14b, the sensor address is not added to the sensor addition list 14c, and the contact sensor 5 whose sensor value is equal to or greater than the threshold value is completely present. In this case, it can be seen that the hand mechanism 1a is not in contact with the object to be grasped, and the hand mechanism 1a is separated from the object to be grasped after the grasping is finished. Therefore, since the sensor list setting unit 12c resets the information collection mode and clears the sensor list 14a (S10), the sensor information collection unit 12a finishes collecting the sensor values of the contact sensor 5.

  Note that whether or not to reset the collection mode may be determined on the condition that a fixed time has passed since the contact sensor 5 whose sensor value is equal to or greater than the threshold value no longer exists, or the camera 4a is connected. The image obtained from the image input unit 16 may be performed after confirming that the grasped object has disappeared from the field of view of the camera 4a. Although not shown in the flow of FIG. 5, in parallel with the above processing, the grip control unit 12b is based on the sensor list 14a in which the contact pressure is recorded, and drive control information for the finger 1b of the hand mechanism 1a. Is output to the drive unit 13.

  In the above description, the sensor list setting unit 12c adds a contact sensor to the sensor addition list 14c, and the sensor list update unit 12d updates the sensor list 14a using the initial sensor list 14b and the sensor addition list 14c. Specifically, this is performed as shown in FIG. FIG. 6 (0-0) shows a part of the contact sensor 5 provided on one finger 1b of the hand mechanism 1a. As shown in FIG. 6 (0-0), each contact sensor 5 has a square shape, and these contact sensors 5 are arranged adjacent to each other. Each of these contact sensors 5 is given a sensor address. For example, in FIG. 6 (0-0), the sensor address of the contact sensor 5 in the second row from the top and the third column from the left is 023. It is.

  FIG. 6 (0-1) shows the selected contact sensor 5 in which the sensor address is registered in the initial sensor list 14b among the contact sensors 5 described above, and the contact sensor 5 surrounded by a thick frame is registered. This is the selected contact sensor 5. In this case, every other vertical and horizontal directions are registered.

  In the process of collecting the sensor values of the contact sensor 5, when the sensor value of the contact sensor 5 of A shown in FIG. 6 (1-1) exceeds the threshold value, the sensor list setting unit 12c is an over-threshold contact sensor. A contact sensor 5 that is one unit distance away from a certain A contact sensor 5, that is, all the contact sensors 5 arranged around the A contact sensor 5, and the A contact sensor 5 itself that is an overthreshold contact sensor Is added to the sensor addition list 14c. FIG. 6 (1-2) shows the contact sensor 5 added to the sensor addition list 14c. When the sensor addition list 14c is as shown in FIG. 6 (1-2) at the time when the collection of the sensor values of all the contact sensors 5 set in the sensor list 14a is completed, the sensor list update unit 12d Using the initial sensor list 14b in FIG. 6 (0-1) and the sensor addition list 14c in FIG. 6 (1-2), the sensor list 14a is updated as shown in FIG. 6 (1-3). That is, all sensor addresses registered in the initial sensor list 14b in FIG. 6 (0-1) and all sensor addresses added in the sensor addition list 14c in FIG. 14a.

  Next, in the process of collecting the sensor values of the contact sensor 5 after the update of the sensor list 14a, if the sensor value of the contact sensor 5 of B shown in FIG. 6, the contact sensors 5 around the contact sensor 5 of B are added to the sensor addition list 14 c as shown in FIG. When the sensor addition list 14c is as shown in FIG. 6 (2-2) when acquisition of the sensor values of all the contact sensors 5 set in the updated sensor list 14a is completed, the sensor list 14a Is updated as shown in FIG. 6 (2-3) by the same process as described above by the sensor list update unit 12d. Similarly, when the sensor value of the contact sensor 5 of C shown in FIG. 6 (3-1) exceeds the threshold value in the process of collecting the sensor values of the contact sensor 5 after the update of the sensor list 14a, As shown in FIG. 6 (3-2), the contact sensors 5 around the C contact sensor 5 are added to the sensor addition list 14c. When the sensor addition list 14c is as shown in FIG. 6 (3-2) when the sensor values of all the contact sensors 5 set in the updated sensor list 14a have been acquired, the sensor list 14a Is updated as shown in FIG. 6 (3-3). At this time, the contact sensor 5 of C ′ shown in FIG. 6 (3-1) is deleted from the sensor list 14a.

  As described above, in the hand (gripping device) 1 described above, the contact pressures of all the contact sensors are not collected initially, but only the selected contact sensors preselected from all the contact sensors are collected. Collect contact pressure. Moreover, the sensor address of the contact sensor 5 from which sensor values should be collected can be changed with the movement of the contact portion of the hand mechanism 1a that comes into contact with the grasped object. Thereby, only the sensor value of the contact sensor 5 at the position where the sensor value needs to be collected is collected along with the movement of the contact part. Therefore, it is possible to efficiently collect information necessary for gripping control, and it is possible to shorten the time for collecting contact pressure. Therefore, according to the hand (gripping device) 1 described above, without reducing the area resolution in the detection of the contact pressure by the contact sensor, that is, without reducing the number of contact sensors used to maintain a high area resolution. The contact pressure of the contact sensor can be collected efficiently, reducing the burden on the information processing system, and reducing the contact pressure collection time to obtain highly reliable data for stable grip control be able to.

  In the above, as the contact sensor 5 having a specific positional relationship with the over-threshold contact sensor, the contact sensor 5 that is 1 unit distance away from the over-threshold contact sensor 5 is used. A distance other than the unit distance may be used. Alternatively, all contact sensors 5 provided in the area of the finger 1b to which the above-threshold contact sensor belongs may be used. FIG. 7 shows an example of this case. When the sensor value of the contact sensor 5 of E in FIG. 7 (4-1) exceeds the threshold value, as shown in FIG. 7 (4-2), All the contact sensors 5 provided in the area of the finger 1b to which the excess threshold contact sensor belongs are added to the sensor addition list 14c.

  In the above, the update process of the sensor list 14a sets all sensor addresses registered in the initial sensor list 14b and all sensor addresses added to the sensor addition list 14c in the sensor list 14a. However, a method of setting only all sensor addresses set in the sensor addition list 14c in the sensor list 14a is also conceivable.

<Embodiment 2>
In the first embodiment, when the hand (grip device) 1 sets the information collection mode in which the sensor list setting unit 12c collects information necessary for the operation of the hand (grip device) 1, It is described as a configuration in which the sensor collection unit 12a immediately starts collecting sensor values of the contact sensor 5 regardless of whether or not the hand mechanism 1a is in contact with the grasped object. However, the sensor value of the contact sensor 5 needs to be collected after the hand mechanism 1a comes into contact with the grasped object. Therefore, a second embodiment in which measures for this point are taken will now be described.

  The hand (gripping device) in the second embodiment is almost the same as the hand (gripping device) 1 in the first embodiment described above. The difference from the first embodiment described above is that of FIG. As shown in the control system configuration in the second embodiment, only the contact determination unit 12e (corresponding to the contact determination means described above) is added to the control unit 12.

  The contact determination unit 12e determines whether or not the hand mechanism 1a has contacted the object to be grasped, and after it is determined that the contact has occurred, the information collection mode by the sensor list setting unit 12c in the first embodiment described above. The operation after the set is performed. Therefore, only the contact determination unit 12e will be described here.

  There are two possible forms of the contact determination unit 12e. One is to monitor the contact pressure, that is, the sensor value detected by all the contact sensors 5 provided on all the fingers 1b of the hand mechanism 1a or the contact sensor 5 of the sensor address set in the initial sensor list. In addition, when one of the sensor values first shows a value different from the state in which the sensor value is not in contact, that is, when the sensor value first changes, it is determined that the hand mechanism 1a has touched the object to be grasped. It is.

  In another embodiment, all the driving loads of the driving unit 13 that drives the plurality of fingers 1b of the hand mechanism 1a are monitored, and when any of the driving loads first exceeds a predetermined value, the hand mechanism 1a It is determined that the object has been touched. This is because the hand (gripping device) performs a gripping operation, and thus it is necessary to move the finger 1b of the hand mechanism 1a, but the contact with the gripping object occurs during the movement, and instantaneously due to the contact, Since the current flowing through the motor used for driving increases, the finger 1b of the hand mechanism 1a grasps by detecting a state in which the driving load first exceeds a predetermined value, such as an increase in the current. It detects that the object has been touched. In this case, not only the plurality of fingers 1b of the hand mechanism 1a but also the driving load of the arm 2 can be included in the monitoring target. Further, whether or not the object to be grasped has been touched may be determined based on an image obtained from the image input unit 16 to which the camera 4a is connected.

<Embodiment 3>
In the first embodiment, only one type of initial sensor list 14b is prepared. However, a plurality of initial sensor lists 14b may be provided according to the type of gripping object. Next, a third embodiment in which this is adopted will be described.

  The hand (gripping device) in the third embodiment is almost the same as the hand (gripping device) in the first embodiment described first, and is different from the first embodiment described above in FIG. As shown in the control system configuration in the third embodiment, the initial sensor list selection unit 12f (corresponding to the above-mentioned initial sensor list selection unit) is added to the control unit 12, and the initial sensor list 14b is used as the gripping object. Only a plurality of points are provided depending on the type.

  In the third embodiment, when the gripping control unit 12b starts control such as driving of the finger 1b by a gripping command from the processing unit 11, a selection command for the type of the gripping object is output from the processing unit 11. Therefore, the initial sensor list selection unit 12f selects one of the plurality of initial sensor lists 14b according to the selection command from the processing unit 11. The processing by the initial sensor list selection unit 12f is performed prior to all processing of the hand (gripping device), and thereafter, the above-described processing is sequentially performed.

  FIG. 9 shows an example of a specific initial sensor list 14b in the third embodiment. In this example, cans, pens, and screws are picked up as objects to be grasped, and the state of operation of the hand mechanism 1a with respect to these is shown in the upper part of FIG. 10 and the contact sensor 5 that needs to collect sensor values is shown. This is shown in the lower part of FIG. Since these contact sensors 5 are narrowed down to only necessary ones, the collection of sensor values can be made efficient by using these initial sensor lists 14b.

  Note that when the processing unit 11 issues a selection command, there are a method for preliminarily specifying a gripping object from the outside, a method for the processing unit 11 to determine by itself based on an image obtained from the image input unit 16 to which the camera 4a is connected, and the like. Conceivable.

  The gripping device described above is realized by a program for causing the gripping device to function.

  The subject of the invention may be the program itself, or the program stored in a computer-readable recording medium.

  In the present invention, as the recording medium, a memory necessary for processing performed by the control unit (microcomputer) 12 shown in FIG. 2, for example, a ROM itself may be a program medium. A program reading device may be provided as an external storage device (not shown), and the program medium may be read by inserting a recording medium therein. In the present invention, the memory provided in the recording unit 14 shown in FIG. 2 is a program medium. In any case, the stored program may be configured to be accessed and executed by the microcomputer, or in any case, the program is read and the read program is a program (not shown) of the microcomputer. It may be a method in which the program is executed after being loaded into the storage area. It is assumed that the loading program is stored in advance in the control unit 12 which is the main body device.

  Here, the program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as an FD (flexible disk) or HD (hard disk), or a CD-ROM / Supports fixed programs including optical disks such as MO / MD / DVD, card systems such as IC cards (including memory cards) / optical cards, and semiconductor memories such as mask ROM, EPROM, EEPROM, flash ROM, etc. It may be a medium.

  Further, in the present invention, since the system configuration is connectable to a communication network including the Internet, the medium may be a medium that dynamically carries the program so as to download the program from the communication network. When the program is downloaded from the communication network in this way, the download program may be stored in the apparatus main body in advance or may be installed from another recording medium. The content stored in the recording medium is not limited to a program, and may be data.

  Furthermore, in the present invention, the program itself may be the process itself executed by the control unit (microcomputer) 12 shown in FIG. 2, or it can be taken in or taken in by accessing a communication network including the Internet. It may be a thing or a thing sent out here. Furthermore, a result obtained by processing in the gripping device based on the fetched program, that is, a generated result may be used. Alternatively, it may be a result of processing in the gripping device when sent from here, that is, a generated result. In addition, these things are not limited to a program, Data may be sufficient.

  The gripping apparatus, gripping control method, and gripping control program of the present invention can be used for use in production sites such as factories.

(a) is a general view of the humanoid robot in Embodiment 1, and (b) is a general view of a hand mechanism of a hand (gripping device) as a part thereof. 2 is a system configuration diagram of control of a humanoid robot in Embodiment 1. FIG. 3 is a system configuration diagram of control of a hand (gripping device) in Embodiment 1. FIG. 2 is a circuit configuration diagram of a contact sensor in Embodiment 1. FIG. 3 is an operation flowchart of the hand (grip device) in the first embodiment. 6 is an explanatory diagram of sensor list update processing according to Embodiment 1. FIG. FIG. 12 is an explanatory diagram of another example of sensor list update processing in the first embodiment. FIG. 10 is a system configuration diagram of control of a hand (grip device) in the second embodiment. FIG. 10 is a system configuration diagram of control of a hand (gripping device) in a third embodiment. FIG. 20 is an explanatory diagram of an initial sensor list in the third embodiment.

Explanation of symbols

1 Hand (gripping device)
1a hand mechanism 1b finger 2 arm 3 body 4 head 4a camera 5 contact sensor 10 humanoid robot 11 processing unit 12 control unit 12a sensor information collection unit 12b grip control unit 12c sensor list setting unit 12d sensor list update unit 12e contact determination unit 12f Initial sensor list selection unit 13 Drive unit 14 Recording unit 14a Sensor list 14b Initial sensor list 14c Sensor addition list 15 Sensor unit 16 Image input unit 17 Power supply unit

Claims (17)

A multi-fingered hand-type gripping means comprising a plurality of independently drivable fingers and gripping a gripping object using the fingers;
Driving means for driving the finger;
A plurality of the fingers, and a contact sensor that detects a contact pressure with an object to be gripped that is in contact with the finger and has a sensor address assigned thereto;
An initial sensor list in which sensor addresses of selected contact sensors selected from the plurality of contact sensors are registered in advance;
Sensor list setting means for initially setting the sensor address registered in the initial sensor list in the sensor list;
Sensor list updating means for performing update processing of the sensor list;
Sensor information collecting means for sequentially collecting contact pressures of contact sensors of all sensor addresses set in the sensor list and recording them in the sensor list each time the initial setting or the update process is performed; ,
A gripping apparatus comprising: drive control means for calculating drive information of the finger based on the contact pressure and providing the calculated information to the drive means. The sensor list setting means determines whether or not the contact pressure exceeds a predetermined threshold every time contact pressure is sequentially collected by the sensor information collecting means, and exceeds the threshold when the contact pressure is exceeded. Set the sensor address of the sensor and the sensor address of the contact sensor in a specific positional relationship with the over-threshold contact sensor in the sensor addition list,
The sensor list updating means, after the collection of contact pressures for contact sensors of all sensor addresses of the sensor list by the sensor information collecting means, is completed based on the information of the sensor addition list and the initial sensor list. The gripping apparatus according to claim 1, wherein update processing is performed.   The gripping device according to claim 2, wherein the contact sensors in the specific positional relationship are all sensors separated by one unit distance from the over-threshold contact sensor.   4. The gripping device according to claim 2, wherein only the sensor address set in the sensor addition list and the sensor address registered in the initial sensor list are set in the sensor list as the update process.   The contact pressure detected by a plurality of contact sensors or contact sensors with sensor addresses registered in the initial sensor list is monitored, and when any of the contact pressures changes for the first time, the sensor list setting means 5. The gripping device according to claim 1, further comprising a contact determination unit that gives an instruction to initially set a sensor address registered in the initial sensor list in the sensor list.   The driving load of the driving means for driving the finger is monitored, and when the driving load exceeds a predetermined value, the sensor list is registered with the sensor address registered in the initial sensor list. The gripping device according to any one of claims 1 to 4, further comprising contact determination means for performing an initial setting instruction.   The sensor information collecting unit stops collecting contact pressure from the contact sensor when all the sensor addresses of the sensor list updated by the sensor list updating unit are the same as the initial sensor list. The gripping device according to any one of claims 1 to 6.   A plurality of initial sensor lists are provided according to the type of the gripping object, and initial sensor list selection means for selecting any initial sensor list for initial setting of the sensor list based on a provided selection command is provided. The gripping device according to any one of claims 1 to 7. A plurality of fingers that can be driven independently, a multi-fingered hand holding means for holding a holding object using the fingers, a driving means for driving the fingers, and a plurality of the fingers. The contact pressure with the object to be gripped in contact with each other is detected, and the contact sensor to which each sensor address is assigned and the sensor address of the selected contact sensor selected from the plurality of contact sensors are registered in advance. A gripping control method in a gripping device including an initial sensor list and a driving control unit that calculates finger driving control information based on the contact pressure and provides the driving unit to the driving unit,
A sensor list setting step for initially setting the sensor address registered in the initial sensor list in the sensor list;
An update process step for performing an update process of the sensor list;
Each time the initial setting or the updating process is performed in the sensor list setting step or the update processing step, the contact pressure is sequentially collected for the contact sensors of all sensor addresses set in the sensor list, and the sensor Collecting sensor information to be recorded in the list;
For each contact pressure collection performed sequentially by the sensor information collecting step, it is determined whether or not the contact pressure exceeds a predetermined threshold, and if it exceeds, the sensor address of the over-threshold contact sensor that exceeds the threshold, and A sensor addition list setting step of setting an address of a contact sensor in a specific positional relationship with the threshold excess contact sensor in a sensor addition list,
The update processing step updates the sensor list based on the information of the sensor addition list and the initial sensor list after the collection of contact pressures for the contact sensors of all sensor addresses of the sensor list in the sensor information collection step. A gripping control method characterized by performing processing.   The grip control method according to claim 9, wherein in the sensor addition list setting step, all sensors separated by one unit distance from the over-threshold contact sensor are recognized as contact sensors in the specific positional relationship.   The grip control method according to claim 9 or 10, wherein in the update process step, as the update process, only the sensor address set in the sensor addition list and the sensor address registered in the initial sensor list are set in the sensor list. .   A contact determination that monitors the contact pressure detected by the contact sensors of the plurality of contact sensors or sensor addresses registered in the initial sensor list and detects when any of the contact pressures changes first as a contact start time. The grip control method according to any one of claims 9 to 11, wherein the step is executed before the execution of the sensor list setting step.   The contact determination step of monitoring the drive load of the drive means for driving the finger and detecting when the drive load exceeds a predetermined value as the contact start time is executed before the execution of the sensor list setting step. The holding | grip control method of any one of Claims 9-11.   When all sensor addresses of the sensor list updated by the sensor list update step are the same as the initial sensor list, a sensor stop step for stopping the collection of contact pressure from the contact sensor is performed. The holding | grip control method of any one of Claims 9-13 formed by replacing with a step.   An initial sensor list selection step that includes a plurality of initial sensor lists according to the type of the gripping object and selects any initial sensor list for initial setting of the sensor list based on a provided selection command. The grip control method according to any one of claims 9 to 14, wherein the grip control method is performed before execution of the contact determination step, and before the sensor list setting step when there is no contact determination step.   The grip control program which makes a computer perform each step of the grip control method of any one of Claims 9-15. A computer-readable recording medium on which the grip control program according to claim 16 is recorded.

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