JP3147637B2 - Gripping device with gripping temperature control function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gripping device for gripping an object gripping portion having a wide temperature range in a lunar base, a planetary base, a space station or the like where environmental conditions (particularly temperature conditions) are severe.

[0002]

2. Description of the Related Art FIG. 8 is an explanatory view showing an outline of a gripping mechanism to which the present invention is applied. For example, the gripping device 10 attached to the tip of a robot arm or the like includes a first gripping means 20 at the tip of the main body 12. The gripping means 20 has three claws 22, and the claws 22 are opened and closed by remote control. A TV camera 14 and the like are provided on an outer peripheral portion of the main body 12 of the gripping device 10 to monitor a gripping operation.
The object 50 to be gripped is, for example, an artificial satellite or the like in outer space, and includes a second gripping means 60 at an end of the main body 52. The second gripping means 60 includes, for example, the first gripping means 2
There is a slit 62 with which the zero pawl 22 is engaged, and the slit 62 is provided with a tapered guide surface 63 for guiding the pawl 22. This type of gripping device is disclosed in Japanese Patent Laid-Open No. 1-169.
No. 121 discloses this.

When the object 50 is gripped, the gripping device 10 is brought close to the object 50 by operating a robot arm or the like.
The claws 22 of the first gripping means 20 are inserted into the slits 62 of the second gripping means 60 of the object 50, and the two are connected. By this connection, the electrical connectors 30 and 35 provided on the gripping device 10 become the electrical connectors 32 and
37 and both are electrically connected. If necessary, a shaft 24 is provided at the center of the gripping device 10 and a shaft 64 corresponding to the object 50 is also provided, so that torque can be transmitted from the gripping device 10 to the object 50. In space, etc., the temperature state fluctuates more than the temperature state on Earth,
A device that measures the temperature of a space navigation object and controls the temperature is disclosed in, for example, JP-A-3-57799 and JP-A-2-279.
No. 499, and the like. Similarly, there is a case where the temperature state of the gripping part of the gripping device used in the outer space is significantly different from the temperature state of the gripping part of the gripping object. That is, the allowable temperature range of the gripping device that is thermally critical among the gripping device and the object gripping portion is set, and the allowable temperature range of the object gripping portion is determined from the mechanical control conditions (material, linear expansion coefficient, fit, etc.). Is set.

FIG. 9 is an explanatory diagram showing the setting of the allowable temperature. That is, thermal design is performed on the target object so that the grip portion is within the allowable temperature range. However, since passive heat control is mainly performed for an object, temperature data of the object gripping portion cannot be measured in many cases. Therefore, this design method is effective for an artificial satellite in which environmental conditions (particularly, temperature conditions) are known and the temperature of an object can be predicted, but the environmental conditions change significantly or the temperature of the object cannot be predicted. In systems (lunar base, planetary base, etc.), the temperature of the object to be gripped may be out of the allowable temperature range. There is a problem that it cannot be determined whether or not it is possible to hold.

[0005]

In order to determine whether or not the object to be grasped can be grasped by the grasping device, it is necessary that the temperature of the object grasping portion can be measured by the grasping device. Also,
Actually, even if the object gripping part is out of the allowable temperature range, the object can be gripped if the temperature difference between the gripping device and the object to be gripped is within the allowable temperature range. In other words, if the temperature of the gripping device and the object to be gripped can be measured and the mechanical conditions (material, coefficient of linear expansion, fit, etc.) of each other are known, whether the gripping device can mechanically grip the object gripping part Can be determined. Even if it is determined that gripping is not possible, gripping is possible if the temperature falls within the allowable temperature difference. Therefore, a function is required to control the temperature of the object to be grasped or the grasping device itself and to make the temperature difference achievable so that the grasping device can grasp the object to be grasped. Accordingly, an object of the present invention is to provide a gripping device that has a function of directly or indirectly measuring the temperature of the gripping device and the target object, and controlling the temperature of the target object or the gripping device itself to be within a temperature difference at which gripping is possible. Is to do.

[0006]

In order to achieve the above object, a temperature sensor is provided for measuring the temperature of the gripping device and the object, and for directly or indirectly measuring the temperature of the gripping object and the gripping device itself. Alternatively, an infrared sensor is used. Next, from the temperature of the object and the gripping device and the mechanical conditions (material, linear expansion coefficient, fit, etc.) of each other, a calculation function is provided for determining whether gripping is possible or for calculating a temperature difference capable of gripping. In order to control the temperature difference between the object and the gripping device within an allowable range, the gripping device is provided with a function of controlling the temperature of the object or a function of controlling the temperature of the gripping device itself. As the former, for example, there is a method of heating an object by radiation light such as razor light. As the latter, the gripping device is heated by a built-in heater, or cooled by increasing the heat radiation surface to control the temperature.

[0007]

According to the present invention, the temperature of the grip is actively controlled. Therefore, environmental conditions (especially temperature conditions) change remarkably, and the temperature of the object
Even when the temperature cannot be within the allowable temperature range, the object can be gripped by the gripping device.

[0008]

FIG. 1 is an explanatory view showing a first embodiment of the present invention. The robot arm, generally designated by the reference numeral 180, is supported by, for example, the space station main body 182 and includes a plurality of joints 184, 188, 192 and rods 186, 190, so that a highly flexible operation is possible. The gripping device 100 provided at the tip of the robot arm 180 includes a main body 11
The first gripping means 20 is provided at the distal end of the “0”. The configuration of the first gripping means 20 includes the same mechanism as that described with reference to FIG. The object 50 to be gripped is, for example, an artificial satellite, and is provided with a second gripping means 60 at an end of the main body 52. The configuration of the second gripping means 60 also has the same mechanism as that described in FIG.

The gripping device 100 has a heater 120 on the outer periphery of the main body 110 thereof. As the heater 120, for example, an electric heater is used. A first temperature sensor 112 is provided in the main body 110, and the first temperature sensor 112 detects a temperature state of the grip portion A of the first grip means 20. A second temperature sensor 132 is provided at the distal end of the main body 110 equipped with the first gripping means 20, and the probe 130 is provided for the second gripping means 60 of the gripping target 50.
It protrudes to the side. The controller 150 includes a controller 152
, A power supply 154, two control units 160 and 162, and a heater switch 170. First temperature sensor 112
The temperature data of the gripping portion A of the first gripping means 20 sent from the first processing section 160 is processed by the first processing section 160 and sent to the control device 152 as first temperature information 161.

The probe 130 provided at the tip of the gripping device 100 detects the temperature state of the gripping portion B of the second gripping means 60 of the target 50 when the gripping device 100 approaches the target 50. The data is sent from the second temperature sensor 132 to the second processing unit 162 of the control unit. The second temperature information 163 processed by the second processing unit 162 is sent to the control device 152. As the probe 130, a means such as an infrared sensor for measuring the temperature by contacting the grip portion B or by measuring the temperature without contact can be used. The control device 152 controls the input first temperature information 161 and the second temperature information 161.
Based on the temperature information 163, the heater signal 153 is output by an algorithm described later. This heater signal 1
53 turns on and off the heater switch 170 and turns off the power supply 15
4 supplies the electric energy 172 to the heater 120 to perform the temperature management of the gripping portions A and B.

FIG. 2 shows the relationship between the temperatures of the gripping portions A and B and the temperature range in which gripping is possible. In FIG. 3A, the temperature of the gripping portion A is tA, and the temperature of the gripping portion B is tB. The gripping parts are manufactured and adjusted under the reference temperature condition, and when an excessive temperature difference occurs between them, the size of the hameai part changes due to the thermal expansion / contraction of the material, which makes the gripping difficult or difficult. The backlash becomes bigger. In addition, when the temperature difference between the grip portion A and the grip portion B increases after gripping, it may be difficult to release the grip. From these conditions, an allowable temperature range for guaranteeing the grip performance is determined. Assuming that the temperature difference between the gripping portions A and B is ΔT and the temperature difference that can be gripped is T, the following allowable temperature range is obtained. | TA−tB | = ΔT ≦ T─────────────── [1] tAmin ≦ tA ≦ tAmaxmax [2] tBmin ≦ tB ≦ tBmax ────────────────── [3]

Here, tAmin / tAmax, tBmin / tBmax
Is the maximum / minimum temperature at which the mechanical strength and the surface characteristics of the gripping portions A and B can be adapted to gripping. FIG. 2B shows an example in which the expression [1] does not hold. At this time, the gripper A and the gripper B cannot be gripped. To enable gripping, it is necessary to control the temperature of the gripper A or the gripper B so that the expression [1] is satisfied.

FIG. 3 shows an algorithm for judging from the temperature information whether or not a grip is possible. In the process started in step 1000, the temperature tA of the gripping unit A on the gripping device side is measured in step 1010 and sent to the control device via the processing unit. At the same time, in step 1020, the temperature tB of the grip portion B on the object side is measured and sent to the control device. In step 1030, the absolute value of the difference between the temperature tA and the temperature tB and the grippable temperature difference T
And the magnitudes of the numbers are compared. If the temperature difference between tA and tB is within the grippable temperature difference, the process proceeds to step 1040,
It is determined that gripping is possible, and in step 1050, the gripping device 10
0, the gripping operation of the object 50 is executed, and
The process ends at 200.

If the temperature difference between the gripping portions A and B is not within the temperature range at which gripping is possible, the process proceeds to step 1100, where it is determined that gripping is impossible. In step 1110, ON / OFF of the heater switch is instructed, and heating or stopping of heating on the gripping device 100 side is executed. In this state, step 101
Returning to 0,1020, the temperature of the gripping portions A and B is measured again, and the following processing is continued. By the heating operation by the heater, the temperature control can be performed so that the temperature difference between the gripping portion A and the gripping portion B is within the grippable temperature difference.

FIG. 4 is an explanatory view of a gripping device according to another embodiment of the present invention. The gripping device 200 includes the robot arm 1
It has means for holding the object 50 attached to the tip of the object 80. The main body 210 of the gripping device 200 includes an electric thermal louver 220. This electric thermal louver 2
Reference numeral 20 has a function of adjusting the heat radiation area of the holding unit A on the holding device 200 side and controlling the temperature of the holding unit A. The gripping device 200 has a first temperature sensor 212 that measures the temperature of the gripping portion A, and a second temperature sensor 232 that measures the temperature of the gripping portion B on the target object via the probe 230.

The control unit 250 includes a first temperature sensor 212
A first processing unit 260 for processing a temperature signal from
And a second processing unit 262 for processing a temperature signal from the temperature sensor 232 of each of them.
Is sent to the control device 252. The power supply 254 controls the thermal louver 220 provided in the gripping device via the electric thermal louver switch 270. Control device 252
Is based on the temperature information of the gripper A and the gripper B by the same algorithm as the algorithm described in FIG.
An ON / OFF signal 253 is sent to the electric thermal louver switch 270 to control the temperature of the gripper A. With this temperature control, the gripping operation is executed after controlling the temperature difference between the gripper A and the gripper B to be within the grippable temperature difference. Thereby, a mechanically reliable connection can be achieved.

FIG. 5 shows an embodiment of a gripping device capable of controlling the temperature of the gripping object. The grip device 300 is provided at the distal end of the robot arm 180 as in the above-described embodiment. The gripping device 300 includes a light emitting device 320 on a side of the main body 310. This light emitting device 320
For example, light energy such as a laser beam L
It has a function of irradiating toward 0 and heating the grip portion B on the object 50 side. The gripping device 300 includes the robot arm 18
It has means for holding the object 50 attached to the leading end of the object 50. The main body 310 of the gripping device 300 is a light emitting device 320
Is provided. The light emitting device 320 has a function of supplying energy to the grip portion B of the object 50 and controlling the temperature of the grip portion B. The gripping device 300 has a first temperature sensor 312 for measuring the temperature of the gripping portion A and a second temperature sensor 332 for measuring the temperature of the gripping portion B on the object side via the probe 230.

The control unit 350 includes a first temperature sensor 312
A first processing unit 360 for processing a temperature signal from
And a second processing unit 362 for processing a temperature signal from the temperature sensor 332, and the respective temperature information 361, 363
Is sent to the control device 352. The power supply 354 supplies electric energy to the thermal louver 220 mounted on the gripping device via the light switch 370. Control unit 352
Is based on the temperature information of the gripper A and the gripper B by the same algorithm as the algorithm described in FIG.
An ON / OFF signal is sent to the light emitter switch 370 to control the temperature of the gripper B. With this temperature control, the gripping operation is executed after controlling the temperature difference between the gripper A and the gripper B to be within the grippable temperature difference. Thereby, a mechanically reliable connection can be achieved.

Referring to FIG. 6, there will be described an embodiment in which temperature control is performed after gripping to determine whether the gripping state can be maintained. This configuration is the same as that described in FIG. It is determined whether the holding state can be maintained. That is, the gripping device 100 attached to the tip of the robot arm 180 changes its gripping means to the object 5
The target object 50 is gripped by engaging with the gripping means 0. In this coupled state, the first temperature sensor 112 measures the temperature state of the gripping portion A on the gripping device 100 side, and the second temperature sensor 132 is inserted into the gripping portion of the object 50 and , The temperature state of the grip portion B on the object side is measured. First, even after gripping, the temperature tA of the gripper A and the gripper B
Is measured. As for the temperature of the gripping part A and the gripping part B, if the temperature difference is ΔT and the temperature difference that can be gripped is T,
Since it is necessary to cope with the problem before it comes off, the temperature allowance is set to T1 to obtain the following allowable temperature range. | TA−tB | = ΔT ≦ T−T1───────────── [4] tAmin ≦ tA ≦ tAmaxmax [5] tBmin ≦ tB ≦ tBmax ────────────────── [6]

Here, tAmin / tAmax, tBmin / tBmax
Is the maximum / minimum temperature at which the mechanical strength and the surface characteristics of the gripping portions A and B can be adapted to gripping. When equation [4] holds, it is determined that the holding state can be maintained,
The temperature control of the gripper A or the gripper B is continued so that the equation [4] holds. If the formula [4] does not hold, it is determined that the holding state cannot be maintained, and a warning is issued to the system. In addition, the payload to be gripped is brought to a safe place, and the gripping state is released.

FIG. 7 shows an example of an algorithm for determining whether or not the holding state can be maintained. The process started in step 2000 is similar to the process in step 2010 in which the temperature t
A is measured, and in step 2020, the temperature tB of the gripper B is measured. In step 2030, tA and t
The temperature difference of B is compared with the temperature ΔT obtained by subtracting the temperature margin T ₁ from the grippable temperature difference T. If the temperature difference between the gripping part A and the gripping part B is within ΔT, the process proceeds to step 2040, where it is determined that the gripping state can be continued, and in step 2050, the continuation of the current temperature control is instructed. 20
Return to 20. When the temperature difference between the gripping portions A and B is equal to or more than ΔT in step 2030, the process proceeds to step 2100, where it is determined that the gripping state cannot be continued, and step 21 is performed.
At 10, a predetermined warning is issued.

At step 2120, the connection between the gripper A and the gripper B is released by an operation of the operator or automatically, and the process is terminated at step 2200. With the above processing, it is possible to reliably avoid the inconvenience that the gripping state cannot be released due to a temperature change after the gripping device 100 grips the target object. Although FIGS. 6 and 7 describe the case of the first embodiment of the present invention, the management of the holding state is executed by the same algorithm in the case of the holding device according to another embodiment of the present invention. can do.

[0023]

According to the present invention, even when environmental conditions (particularly, temperature conditions) are significantly changed and the temperature of the object to be gripped cannot be within the allowable temperature range only by passive thermal control, the gripping can be performed. The object of the apparatus can be gripped. Further, by measuring the temperatures of the gripping device and the object, and controlling the temperature of the gripping device or the object to be gripped, it is possible to perform a thermomechanical reliable connection.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment according to the present invention.

FIG. 2 is a diagram showing the relationship between the temperatures of the gripping portions A and B and the temperature range in which gripping is possible in the embodiment of the present invention.

FIG. 3 is a diagram showing an algorithm for judging whether or not gripping is possible from temperature information according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of another embodiment according to the present invention.

FIG. 5 is a configuration diagram of another embodiment according to the present invention.

FIG. 6 is a schematic view of a gripping device and an object gripping portion according to the present invention.

FIG. 7 is an explanatory diagram showing a method of setting an allowable temperature range of a gripping device and a target object gripping portion.

FIG. 8 is a schematic diagram of a gripping device to which the present invention is applied.

FIG. 9 is an explanatory diagram showing setting of a conventional allowable temperature range.

[Explanation of symbols]

 Reference Signs List 10 gripping device 20 first gripping means 50 target object 60 second gripping means 100 gripping device 110 main body 112 first temperature sensor 120 heater 130 probe 132 second temperature sensor 150 control unit 152 control device 154 power supply 166 first Processing unit 162 second processing unit 180 robot arm 200 gripping device 220 electric thermal louver 300 gripping device 320 light emitting device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B25J 3/00-3/10 B25J 9/10-9/22 B25J 13/00-13/08 B25J 15 / 00-15/12 B25J 19/02-19/06

Claims (4)

(57) [Claims] 1. A gripping device for gripping an object in a three-dimensional space, wherein the gripping device includes a first gripping device for gripping a second gripping device mounted on the object, and a first gripping device. A first temperature sensor for measuring the temperature of the gripper, a second temperature sensor for measuring the temperature of the gripper of the second gripper, a temperature controller, and a temperature controller based on the temperature information of the gripper. A gripping device having a gripping temperature control function, comprising: 2. The control device according to claim 1, further comprising:
Operating the temperature control means based on the temperature information of
Temperature control so that the difference is within the grippable temperature difference
Bei grip temperature control function according to claim 1, further comprising a Gorizumu
Obtain gripping device. 3. The control device according to claim 1 , wherein the temperature of the grip portion in the grip state is controlled.
Operation of temperature control means based on degree information enables continuation of gripping state
The gripping device having a gripping temperature control function according to claim 1, further comprising an algorithm for controlling the temperature so as to be within the temperature difference . 4. The control device according to claim 1 , wherein the temperature difference of the grip portion is a grip state.
When the continuous temperature difference is exceeded, a warning is issued and the gripping state is released
The gripping device having a gripping temperature control function according to claim 1, further comprising an algorithm for performing the gripping temperature control.