A calibration device for obtaining six degrees of freedom of a tool output end

Abstract

The present invention provides a calibration device for obtaining six degrees of freedom of a tool output end, including a calibration head and a calibration part, wherein the calibration head is used to cooperate with the tool output end, a contact plane is radially arranged on the calibration head, and a reflective marking point and a trigger switch are arranged on the calibration part, and when the contact plane directly or indirectly contacts the trigger switch, an indicator light connected to the trigger switch lights up. The calibration device provided by the present invention can realize fast calibration, and can help users complete the calibration of the tool output end within a few seconds; it can obtain six degrees of freedom information of the tool output end, and simultaneously obtain the center coordinates and direction vector of the tool output end, and can solve the problem that other calibration methods / calibration tools cannot quickly obtain the center of the tool output end, and can reduce the complexity of the calibration of the tool output end, and reduce the learning cost of users.

Description

Technical Field

[0001] The present invention belongs to the technical field of calibration tools, and in particular relates to a calibration device for obtaining six degrees of freedom (center position and direction vector) of a tool output end. Background Art

[0002] In the visual tracking system, the camera obtains the spatial coordinates of the marking points installed on the tool in real time, and the spatial position of the tool can be obtained through these points. In the actual application process, it is necessary to track the spatial position of the tool output end to achieve the purpose of real-time tracking or control of the work process, which requires calibration to calculate the spatial coordinate relationship between the marking point device and the tool output end.

[0003] The existing conventional calibration method is to use a light pen with a measuring head to touch the output end of the tool. In the camera coordinate system, the spatial coordinates of the measuring head of the light pen are known. When the measuring head of the light pen touches the output end of the tool, the spatial coordinates of the touch point can be obtained. Then, the spatial position of the tool output end can be calculated by measuring multiple points on the tool output end through this method. Since the spatial coordinates of the marking point device fixed on the tool are known, the spatial coordinate relationship between the tool output end and the marking point device can be obtained. Using this coordinate relationship, the spatial position of the tool output end can be tracked in real time during use.

[0004] However, the following problems exist when using existing conventional calibration tools and methods: 1. The calibration process is relatively complicated and the errors caused by human factors are unpredictable, and the center position of the output end cannot be accurately obtained. If the output end of the tool is a polygon or a circle, when using a light pen for calibration, if only one point is touched, there will be a problem of inaccurate spatial posture positioning during use; 2. The direction vector of the center point of the tool output cannot be accurately obtained. If the center point and direction vector are to be measured, the number of touch points must be increased, that is, multiple points must be collected on the inner and outer walls of the output end and the end face to fit the center and direction vector of the output end; 3. The calibration of the tool output end needs to be completed on-site, and the professional knowledge and skills of light pen measurement are not easy to be mastered by on-site operators; 4. The accuracy of the tool output end cannot be quickly verified on-site. Summary of the invention

[0005] The object of the present invention is to provide a calibration device for obtaining six degrees of freedom of a tool output end, so as to solve at least one technical problem existing in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solution.

[0007] A calibration device for obtaining six degrees of freedom of a tool output end, characterized in that it includes a calibration head and a calibration part, the calibration head is used to cooperate with the tool output end, a contact plane is radially arranged on the calibration head, and a reflective marking point and a trigger switch are arranged on the calibration part. When the contact plane directly or indirectly contacts the trigger switch, an indicator light connected to the trigger switch lights up.

[0008] In order to improve the calibration accuracy, a limit hole is provided on the calibration part, the limit hole is precisely matched with the calibration head, and the calibration head can only move axially along the limit hole.

[0009] To further improve the calibration accuracy, the calibration head consists of a cylinder and an annular plate fixed on the cylinder. The lower end surface of the annular plate serves as the contact plane, and the upper end surface of the annular plate is used to abut against the output end surface of the tool. The cylinder and the limit hole are precisely matched.

[0010] As one of the preferred schemes of the present invention, the calibration part includes a substrate and a control circuit board arranged on the substrate, reflective marking points and limit holes are arranged on the substrate, and the trigger switch is arranged on the control circuit board; a conductive column is axially arranged in the limit hole, and the conductive column can move axially and contact the trigger switch after being axially compressed.

[0011] As the second preferred solution of the present invention, the calibration part includes a substrate and a control circuit board, a through hole, and a connecting piece arranged on the substrate, the reflective marking point is arranged on the substrate, the limit hole is arranged on the connecting piece, the through hole and the limit hole are coaxially arranged, and the trigger switch is arranged on the control circuit board; a conducting column is axially arranged on the connecting piece and around the limit hole, and the conducting column can move axially after being axially compressed and directly or indirectly contact the trigger switch.

[0012] In the present invention, the indirect contact means that the conducting post and the trigger switch are in contact with each other by means of a conductor; after the calibration head contacts the conducting post and the conducting post contacts the trigger switch directly or indirectly, the indicator light circuit is turned on.

[0013] In order to facilitate multiple calibration operations in succession, an elastic contact piece is provided between the control circuit board and the conducting column. When the conducting column is axially compressed, the elastic contact piece can be driven to move axially, and the elastic contact piece can contact the trigger switch.

[0014] In order to improve the calibration efficiency, at least three trigger switches are provided; a control module and a communication module are also provided on the control circuit board of the calibration part, the control module is connected to the indicator light circuit, and the processing unit of the control module implements the following steps when executing its program:

[0015] When the contact surface does not trigger the switch, the indicator light is red;

[0016] When the contact plane touches all the trigger switches, the indicator light turns green. At this time, a message is sent to the host through the communication module to save the calibration data. After the calibration data is saved successfully, a message is returned to the communication module. After the communication module receives the returned message, the indicator light turns blue and flashes.

[0017] Furthermore, the calibration device also includes a shell plate, which is cooperatively connected with the substrate, and a slot for accommodating a control circuit board is provided on the shell plate. The control circuit board is limited in the slot and is located between the shell plate and the substrate, and the reflective marking point is arranged on the surface of the substrate away from the shell plate.

[0018] The calibration device provided by the present invention has the following advantages:

[0019] (1) It can realize fast calibration, which can help users complete the calibration of the tool output end within a few seconds;

[0020] (2) The operation is simple and in line with the on-site operation habits. When using it, just insert the calibration head installed on the tool into the calibration hole, eliminating the tedious process of collecting multiple points for calibration;

[0021] (3) Accurate positioning and high precision. During the calibration process, the user adjusts the tool posture to the appropriate position according to the indicator light, and the calibration data will be automatically saved, reducing the error caused by human operation. The accuracy can reach 0.2mm;

[0022] (4) The accuracy verification of the tool output end can be completed quickly. Before using the tool each time, the calibration device can be used to quickly verify the accuracy of the tool output end calibration. The usage method is the same as the calibration process, which is conducive to ensuring the reliability of the calibration system;

[0023] (5) The calibration device of the present invention can obtain the six-degree-of-freedom information of the tool output end, and simultaneously obtain the center coordinates and direction vector of the tool output end, which can solve the problem that other calibration methods / calibration tools cannot quickly obtain the center of the tool output end, and can reduce the complexity of the tool output end calibration and reduce the user's learning cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural diagram (schematic diagram) of the calibration device in Example 1;

[0025] Figure 2 is an exploded view (schematic diagram) of the calibration device in Example 1;

[0026] Figure 3 is a structural diagram (schematic diagram) of a calibration head of the calibration device in Example 1;

[0027] Figure 4 This is a usage status diagram of the calibration device in Example 1. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the description of the following embodiments is only used to help understand the principle and core idea of ​​the present invention, and is not intended to limit the scope of protection of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, improvements made to the present invention also fall within the scope of protection of the claims of the present invention.

[0029] Example 1

[0030] See also Figures 1 to 3 A calibration device for obtaining six degrees of freedom of a tool output end includes a calibration head 20 and a calibration part. The calibration head 20 is used to match the tool output end. A contact plane 21 is radially arranged on the calibration head 20. A reflective marking point 9 and a trigger switch 10 are arranged on the calibration part. When the contact plane 21 directly or indirectly contacts the trigger switch 10, an indicator light 11 connected to the trigger switch 10 lights up. A limit hole 12 is arranged on the calibration part. The limit hole 12 is precisely matched with the calibration head 20, and the calibration head 20 can only move axially along the limit hole 12.

[0031] In this embodiment, Figure 3 As shown, the calibration head 20 is composed of a column 22 and an annular plate 23 fixedly arranged on the column 22, the lower end face of the annular plate 23 serves as a contact plane 21, and the upper end face 24 of the annular plate is used to abut against the output end face of the tool, the lower end face of the annular plate 23 and the upper end face 24 of the annular plate 23 respectively refer to the two end faces of the annular plate 23, and the column 22 is precisely matched with the limiting hole 12.

[0032] In this embodiment, Figure 2 As shown, the calibration part includes a substrate 5 and a control circuit board 3, a through hole 8, and a connector 7 arranged on the substrate 5. A reflective marking point 9 is arranged on the substrate 5. A limit hole 12 is arranged on the connector 7. The through hole 8 is coaxially arranged with the limit hole 12. The through hole 8 is used to cooperate with the connector 7 for mounting. A trigger switch 10 is arranged on the control circuit board 3. Three conducting columns 6 of the same specifications are axially arranged on the connector 7 and around the limit hole 12. The conducting columns 6 can move axially and directly or indirectly contact the trigger switch 10 after being axially compressed. An elastic contact piece 4 is arranged between the control circuit board 3 and the conducting column 6. The conducting column 6 can drive the elastic contact piece 4 to move axially after being axially compressed, and the elastic contact piece 4 can contact the trigger switch 10.

[0033] In this embodiment, the calibration device further includes a shell plate 2, which is connected with the base plate 5, and a card slot for accommodating the control circuit board 3 is provided on the shell plate 2. The control circuit board is limited in the card slot and is located between the shell plate 3 and the base plate 5, and the reflective marking point 9 is provided on the surface of the base plate 5 away from the shell plate 2. A battery installation area and a battery protection cover 1 are also provided on the shell plate 2, and the battery installed in the battery installation area provides power for the calibration device.

[0034] In this embodiment, three trigger switches 10 are provided, each trigger switch 10 corresponds to a conducting column 6; a control module and a communication module are also provided on the control circuit board 3 of the calibration part, the control module is connected to the indicator light circuit, and the processing unit of the control module implements the following steps when executing its program:

[0035] When the contact plane 21 does not trigger the trigger switch 10, the indicator light 11 lights up red;

[0036] When the contact plane 21 touches all the trigger switches 10, the indicator light 11 lights up green. At this time, a message is sent to the host through the communication module to save the calibration data. After the calibration data is saved successfully, a message is returned to the communication module. After the communication module receives the returned message, the indicator light 11 turns blue and flashes.

[0037] The assembly process of the calibration device in this embodiment is as follows: first, a reflective mark is attached to the corresponding position of the substrate 5, then the connector 7, the conducting column 6, and the elastic contact sheet 4 are installed on the substrate 5, then the control circuit board 3 is installed in the card slot of the shell plate 2, the battery is installed in the battery installation area, the battery protection cover 1 is buckled, and then the shell plate 2 and the substrate 5 are assembled. After the assembly is completed, the light-emitting area of ​​the indicator light 11 is located at Figure 1 The part indicated by number 13 in the figure.

[0038] Specifically, the substrate 5 and the connector 7 are made of materials that meet the rigidity requirements. The elastic contact piece 4 is composed of a plate body and a spring connected to the plate body, and the other end of the spring is connected to the control circuit board 3. When in use, the calibration head 20 is driven by an external force to press down the conductive column 6, so that when the conductive column 6 presses down the elastic contact piece 4, the spring is compressed and the plate body moves with the spring; when the external force is removed, the spring is reset and drives the conductive column 6 to reset.

[0039] The method of using the calibration device in this embodiment is as follows:

[0040] Step 1, installing the calibration head 20: during installation, insert the end of the calibration head 20 that matches the tool 19 into the tool output end, ensuring that the tool output end contacts the back of the calibration head contact plane (i.e., the upper end surface 24 of the annular plate 23 contacts the tool output end surface);

[0041] Step 2, start calibration: Figure 4As shown, the front end of the column of the calibration head 20 is inserted into the calibration hole (i.e., the limit hole 12) of the calibration part. At this time, the contact plane of the calibration head will compress the elastic contact piece 4 through the conductive column 6. When the conductive column is fully pressed down, the trigger switch 10 on the control circuit board 3 can be triggered. At this time, if the three indicator lights 11 of the calibration part all turn green, it means that the posture of the tool has been adjusted to a suitable position, that is, the contact surface 21 of the annular plate is in full contact with the upper end surface of the connector 7; if the indicator lights 11 of the calibration part show two green and one red, it means that the posture of the tool has not been adjusted to a suitable position. At this time, it is necessary to continue to adjust the posture of the tool until the three indicator lights all turn green;

[0042] Step 3, waiting for calibration data to be saved: when the posture is adjusted to a suitable position, the three indicator lights 11 will turn green, and the user needs to maintain the posture and wait for the host to save the calibration data (about 1-2 seconds);

[0043] Step 4, calibration completed: After the host successfully saves the calibration data, it will return a message, and the indicator light 11 will turn blue and flash.

[0044] The calibration principle of the calibration device in the present invention is as follows: a rigid coordinate system Q is established with the reflective points (reflective marking points 9) on the calibration plate, and the relative relationship between the center O of the upper end face of the calibration hole (i.e., the limit hole 12) and the direction vector N of the end face and the rigid coordinate system Q is measured using a visual system, wherein N points to the axial direction of the limit hole 12; during calibration, a local coordinate system C is established with the marking point device on the tightening gun to be calibrated, and the conversion relationship {R, T} between the calibration plate coordinate system Q and the local coordinate system C is obtained through the camera coordinate system. When the calibration head compresses the elastic contact piece 4 and turns on the three trigger switches 10, the coordinate value of the center O of the calibration hole at this time in the rigid coordinate system Q is automatically saved. At this time, it is approximately considered that the center points M and O of the contact plane of the calibration head coincide, that is, the coordinate value of the center point M of the contact plane in the rigid coordinate system Q is obtained. According to the conversion relationship {R, T}, the coordinate M'=RM+T of M in the local coordinate system C is obtained. Similarly, the representation N' of the direction vector N of the tool output end in the local coordinate system C can be calculated. It is known that the thickness of the annular plate 23 of the calibration head is Th, then after M' moves Th in the opposite direction of N', the center point M1' of the end face of the tool output end is obtained, and the vector remains unchanged as N', (M1', N'), which is a complete description of the six degrees of freedom of the tool output end. Because the marking point device is fixed on the tool and constitutes a rigid body, the coordinates of the tool output end in the local coordinate system C are constant, that is, the spatial relative position of the tool output end and the marking point device is unchanged.

[0045] Example 2

[0046] A calibration device for obtaining six degrees of freedom of a tool output end includes a calibration head and a calibration part. The calibration head is used to match the tool output end. A contact plane is radially arranged on the calibration head. A reflective marking point and a trigger switch are arranged on the calibration part. When the contact plane directly or indirectly contacts the trigger switch, an indicator light connected to the trigger switch lights up. A limit hole is arranged on the calibration part. The limit hole is precisely matched with the calibration head, and the calibration head can only move axially along the limit hole.

[0047] In this embodiment, the calibration head consists of a cylinder and an annular plate fixed on the cylinder. The lower end surface of the annular plate serves as a contact plane, and the upper end surface of the annular plate is used to abut against the output end surface of the tool. The lower end surface of the annular plate and the upper end surface of the annular plate refer to the two end surfaces of the annular plate respectively, and the cylinder is precisely matched with the limit hole.

[0048] In this embodiment, the calibration part includes a substrate and a control circuit board arranged on the substrate, reflective marking points and limit holes are arranged on the substrate, and the trigger switch is arranged on the control circuit board; a conductive column is axially arranged in the limit hole, and the conductive column can move axially and contact the trigger switch after being axially compressed.

[0049] In this embodiment, the calibration device further includes a shell plate, which is connected to the base plate in cooperation, and a slot for accommodating a control circuit board is provided on the shell plate, the control circuit board is limited in the slot and is located between the shell plate and the base plate, and the reflective marking point is provided on the base plate surface away from the shell plate. A battery installation area and a battery protection cover are also provided on the shell plate, and the battery installed in the battery installation area provides power for the calibration device.

[0050] In this embodiment, three trigger switches are provided, each trigger switch corresponds to a conduction column; a control module and a communication module are also provided on the control circuit board of the calibration part, the control module is connected to the indicator light circuit, and the processing unit of the control module implements the following steps when executing its program:

[0051] When the contact surface does not trigger the switch, the indicator light is red;

[0052] When the contact plane touches all the trigger switches, the indicator light turns green. At this time, a message is sent to the host through the communication module to save the calibration data. After the calibration data is saved successfully, a message is returned to the communication module. After the communication module receives the returned message, the indicator light turns blue and flashes.

[0053] In the present invention, the number of the conducting columns includes but is not limited to three, and may be more; the number of the reflective marking points is determined by those skilled in the art according to actual conditions.

[0054] In the present invention, the connector 7 and the through hole 8 can be arranged at any position on the substrate 5 and are not limited by the installation angle; the installation position and angle are determined by those skilled in the art according to actual conditions.

Claims

1. A calibration device for obtaining six degrees of freedom of a tool output end, characterized in that: It comprises a calibration head (20) and a calibration part. The calibration head (20) is used to match the output end of the tool. A contact plane (21) is radially arranged on the calibration head (20). A reflective marking point (9) and a trigger switch (10) are arranged on the calibration part. When the contact plane (21) directly or indirectly contacts the trigger switch (10), an indicator light (11) connected to the trigger switch (10) lights up. The calibration head (20) is composed of a column (22) and an annular plate (23) fixedly arranged on the column (22); the lower end surface of the annular plate (23) serves as a contact plane (21); the upper end surface (24) of the annular plate is used to abut against the output end surface of the tool; the lower end surface of the annular plate (23) and the upper end surface (24) of the annular plate (23) respectively refer to two end surfaces of the annular plate (23); the column (22) and the limiting hole (12) are precisely matched; The calibration part comprises a substrate (5) and a control circuit board (3) arranged on the substrate (5); a reflective marking point (9) and a limit hole (12) are arranged on the substrate (5); and a trigger switch (10) is arranged on the control circuit board (3); a conducting column (6) is axially arranged in the limit hole (12); and the conducting column (6) can move axially and contact the trigger switch (10) after being axially compressed; Three trigger switches (10) are provided.

2. The calibration device according to claim 1, characterized in that: A limiting hole (12) is provided on the calibration portion, the limiting hole (12) is precisely matched with the calibration head (20), and the calibration head (20) can only move axially along the limiting hole (12).

3. The calibration device according to claim 2, characterized in that: The calibration head (20) is composed of a column (22) and an annular plate (23) fixedly arranged on the column (22); the lower end surface of the annular plate (23) serves as a contact plane (21); the upper end surface (24) of the annular plate is used to abut against the output end surface of the tool; the column (22) is precisely matched with the limiting hole (12).

4. The calibration device according to claim 3, characterized in that: The calibration part comprises a substrate (5), a control circuit board (3), a through hole (8), and a connecting piece (7) arranged on the substrate (5); a reflective marking point (9) is arranged on the substrate (5); a limit hole (12) is arranged on the connecting piece (7); the through hole (8) and the limit hole (12) are coaxially arranged; and a trigger switch (10) is arranged on the control circuit board (3); a conducting column (6) is axially arranged on the connecting piece (7) and around the limit hole (12); the conducting column (6) can move axially after being axially compressed and directly or indirectly contact the trigger switch (10).

5. The calibration device according to claim 4, characterized in that: An elastic contact piece (4) is arranged between the control circuit board (3) and the conducting column (6); the conducting column (6) can drive the elastic contact piece (4) to move axially after being axially compressed, and the elastic contact piece (4) can contact the trigger switch (10).

6. The calibration device according to any one of claims 1 to 5, characterized in that: A control module and a communication module are also provided on the control circuit board (3) of the calibration part. The control module is connected to the indicator light circuit. When the processing unit of the control module executes its program, the following steps are implemented: When the contact plane (21) does not trigger the trigger switch (10), the indicator light (11) lights up red; When the contact plane (21) triggers all the trigger switches (10), the indicator light (11) lights up green, and the communication module sends A message is sent to the host computer so that it can save the calibration data. After the calibration data is successfully saved, a message is returned to the communication module. After the communication module receives the returned message, the indicator light (11) turns blue and flashes.

7. The calibration device according to claim 6, characterized in that: The calibration device also includes a shell plate (2), the shell plate (2) being cooperatively connected with the base plate (5), a slot for accommodating a control circuit board (3) being provided on the shell plate (2), the control circuit board being limited in the slot and being located between the shell plate (2) and the base plate (5), and a reflective marking point (9) being provided on a surface of the base plate (5) away from the shell plate (2).

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