Error adjustment method and compensation device for attitude change of multi-link parallel assembly and adjustment

Abstract

The present invention relates to the technical field of mechanical assembly and adjustment, and provides a compensation method and device for attitude change in multi-link parallel assembly and adjustment. The method includes the following steps: obtaining the designed length of the link assembly and measuring the actual length of the link assembly; establishing an assembly error model for the buffer base according to the actual length and the designed length; substituting the actual length into the assembly error model to calculate the compensation amount; removing all the link assemblies and replacing them with error adjustment and compensation devices for attitude change in multi-link parallel assembly and adjustment with the same quantity; implementing compensation according to the compensation amount; reinstalling all the link assemblies and padding adjustment pads into the link assemblies. And a compensation device is designed for the compensation method of the present invention. The present invention solves the technical problem that the attitude of the buffer base is reduced due to different lengths of each link, and achieves the technical effects of improving the assembly accuracy, enhancing the stability of the buffer base, being easy to implement, and having strong versatility.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical assembly and adjustment, and particularly relates to a method for error of attitude change in multi-link parallel assembly and adjustment and a compensation device. Background Art

[0002] In the process of assembling and adjusting a multi-link parallel mechanism, due to factors such as manufacturing errors and assembly errors, the actual length of the connecting rod often deviates from the designed length to a certain extent. In the process of multi-link parallel assembly and adjustment, the smaller the adjustment error of the equipment, the smaller the attitude change of the equipment output. The attitude change will directly affect the motion accuracy and stability of the parallel mechanism. During assembly, the machining dimension error of parts, the measurement dimension error, and the error generated during assembly are likely to cause the length dimensions of the connecting rod components to be inconsistent, resulting in dimensional deviations between the connecting rods, which will affect the attitude accuracy of the buffer base, thereby affecting the performance of the buffer base and causing quality problems. Therefore, the dimensional accuracy of each connecting rod component determines the overall performance change of the entire buffer base. Among them, assembly adjustment is one of the key links in the assembly of the buffer base. Therefore, an effective error compensation method is needed to achieve the change of position and attitude.

[0003] The existing multi-link parallel buffer base used in technical means consists of a top plate, 16 connecting rod components, a bottom plate, and 32 spherical hinges. Due to factors such as manufacturing errors and assembly errors, the actual length of the connecting rod components often deviates from the designed length to a certain extent. In the process of multi-link parallel assembly and adjustment, the smaller the adjustment error of the equipment, the smaller the attitude change of the equipment output. The attitude change will directly affect the motion accuracy and stability of the parallel mechanism. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. For this purpose, the present invention provides a method for error adjustment of attitude change in multi-link parallel assembly and adjustment and a compensation device, which can improve the measurement accuracy and speed up the measurement speed.

[0005] The present invention provides a method for error adjustment of attitude change in multi-link parallel assembly and adjustment, including the following steps:

[0006] S1: Obtain the designed length of the connecting rod component and measure the actual length of the connecting rod component;

[0007] S2: Establish an assembly and adjustment error model of the buffer base;

[0008] S3: Substitute the actual length and the designed length into the assembly and adjustment error model to calculate the compensation amount;

[0009] S4: Record the state of the connecting rod component before disassembly, remove all the connecting rod components from the multi-link parallel buffer base, and replace them with error adjustment and compensation devices for multi-link parallel assembly and adjustment with the same quantity;

[0010] S5: According to the compensation amount, use the error adjustment compensation device for adjusting the attitude change of the multi-link parallel assembly to implement compensation, adjust the position of the top plate of the multi-link parallel buffer base, and manufacture an adjustment pad;

[0011] S6: Install the adjustment pad at the top or bottom of the link assembly, and then reinstall all the link assemblies with the adjustment pads installed back to the state before the disassembly of the link assembly, completing the error adjustment of the attitude change of the multi-link parallel assembly.

[0012] According to the present invention, a method for adjusting the error of the attitude change of a multi-link parallel assembly is provided, and step S2 includes:

[0013] S21: Establish a fixed coordinate system with the center of the bottom plate of the buffer base as the origin , and use the direction from the center of the bottom plate of the buffer base to the edge of the bottom plate of the buffer base as the positive direction of the axis of the fixed coordinate system, use the direction perpendicular to the bottom plate of the buffer base and upward as the positive direction of the axis, the positive direction of the axis can form a right-handed coordinate system with the axis and the positive direction of the axis, and define the coordinates of the center of the spherical hinge above the bottom plate of the buffer base; the axis of the fixed coordinate system, and use the direction from the center of the top plate of the buffer base to the edge of the top plate of the buffer base as the positive direction of the

[0014] Establish a moving coordinate system with the center of the top plate of the buffer base as the origin , and use the direction from the center of the top plate of the buffer base to the edge of the top plate of the buffer base as the positive direction of the axis of the moving coordinate system, use the direction perpendicular to the top plate of the buffer base and upward as the positive direction of the axis, the positive direction of the axis can form a right-handed coordinate system with the axis and the positive direction of the axis, and define the coordinates of the center of the spherical hinge below the top plate of the buffer base; the axis of the moving coordinate system, and define the coordinates of the center of the spherical hinge below the top plate of the buffer base;

[0015] S22: Establish the dynamic equations of the link assembly, the clearance error of the spherical hinge, and the pose error of the top plate:

[0016]

[0017] Among them, is the length precision matrix, is the clearance precision matrix, is the precision error, is the length error of the connecting rod assembly, is the clearance error of the ball hinge, and the dynamic equation is the alignment error model of the buffer base.

[0018] According to the present invention, an error adjustment method for attitude change in multi-link parallel alignment is provided. S22 includes:

[0019]

[0020]

[0021]

[0022]

[0023] Among them, is the i coordinate of the center of the ball of the i ball hinge under the top plate of the buffer base corresponding to the th connecting rod assembly of the top plate, transformed from the moving coordinate system to the fixed coordinate system and is expressed as the unit vector corresponding to the direction vector i of the th connecting rod assembly, is the coordinate of the center of the ball of the ball hinge above the bottom plate of the i th buffer base, i is the sequence number of the connecting rod assembly, represents the position vector relative to the origin of the moving coordinate system , is expressed as the rotation matrix of the moving coordinate system relative to the fixed coordinate system , is the damping vector of the center of the ball of the i th ball hinge on the top plate of the buffer base in the moving coordinate system , represents matrix transpose.

[0024] According to the present invention, an error adjustment method for attitude change in multi-link parallel alignment is provided. In step S3, according to the perturbation theory transformation , such that becomes the zero matrix, when is the zero matrix, the corresponding

[0025] According to the present invention, there is provided an error adjustment method for the attitude change of a multi-link parallel assembly and adjustment, and step S5 includes: according to the compensation amounts of different link components, using a host computer to control an error adjustment compensation device for the attitude change of the multi-link parallel assembly and adjustment to perform adjustment, and the difference between the length of the error adjustment compensation device for the attitude change of the multi-link parallel assembly and adjustment and the actual length of the link component is the thickness of the adjustment pad.

[0026] According to the present invention, there is provided an error adjustment method for the attitude change of a multi-link parallel assembly and adjustment. When there is a negative value in the compensation amount, first extend all the error adjustment compensation devices for the attitude change of the multi-link parallel assembly and adjustment by the same length, and then perform the adjustment. The same extended length is greater than the compensation amount.

[0027] The present invention provides an error adjustment compensation device for the attitude change of a multi-link parallel assembly and adjustment, which is used to execute the above error adjustment method for the attitude change of a multi-link parallel assembly and adjustment, and includes: a servo motor, a reduction mechanism, a rotating member, and a movable push rod;

[0028] The output end of the servo motor is connected to the bottom end of the reduction mechanism;

[0029] The top end of the reduction mechanism is connected to the bottom end of the rotating member;

[0030] A groove is provided inside the rotating member, and a thread is provided on the inner surface of the groove;

[0031] A thread is provided on the outer surface of the movable push rod, and the movable push rod is screwed into the groove inside the rotating member.

[0032] According to the present invention, an error adjustment compensation device for the attitude change of a multi-link parallel assembly and adjustment further includes: a guide cylinder, a cylinder body, a bottom cover, and a thrust bearing;

[0033] The rotating member and the movable push rod are installed inside the guide cylinder;

[0034] The servo motor and the reduction mechanism are installed inside the cylinder body;

[0035] The bottom cover is installed at the bottom of the cylinder body;

[0036] The inner ring of the thrust bearing is connected to the rotating member;

[0037] The outer ring of the thrust bearing is connected to the cylinder body.

[0038] The reduction mechanism of the error adjustment compensation device for the attitude change of a multi-link parallel assembly and adjustment according to the present invention further includes: a first gear, a first gear set, a second gear set, and a second gear;

[0039] The servo motor shaft hole of the first gear is connected to the output end of the servo motor, and the first gear is used to receive the output of the servo motor;

[0040] The teeth of the first gear set mesh with the teeth of the first gear;

[0041] The bottom end of the shaft of the second gear set is inserted into the shaft hole of the first gear set, and the teeth of the second gear set mesh with the teeth of the second gear;

[0042] The shaft of the second gear is connected to the bottom of the rotating member, and is used to transmit the input of the servo motor after deceleration to the rotating member.

[0043] According to the present invention, a speed reduction mechanism of an error adjustment and compensation device for attitude change of a multi-link parallel assembly and adjustment further includes: a first ball bearing group, a second ball bearing group, a third ball bearing, a bearing gland, a lock nut, a bearing pressing plate and a gear bracket;

[0044] The gear bracket is installed above the servo motor;

[0045] The first ball bearing group is installed at the bottom of the gear bracket, and the bottom end of the shaft of the second gear set is inserted into the inner ring of the first ball bearing group;

[0046] The second ball bearing group is installed at the bottom of the bearing gland, and the top end of the shaft of the second gear set is inserted into the inner ring of the second ball bearing group;

[0047] The third ball bearing is installed at the center of the bearing gland, and the top end of the shaft of the second gear is inserted into the inner ring of the third ball bearing;

[0048] The lock nut is installed above the inner ring of the third ball bearing and the shaft of the second gear, and is used to lock the top end of the shaft of the second gear and the third ball bearing;

[0049] The bearing pressing plate is located above the lock nut, and the bearing pressing plate is used to press the lock nut.

[0050] An error adjustment method and compensation device for attitude change of a multi-link parallel assembly and adjustment provided by the present invention realizes the following by creating an error adjustment method and designing an error adjustment and compensation device for attitude change of a multi-link parallel assembly and adjustment: improving the motion accuracy, significantly improving the motion accuracy of the multi-link parallel mechanism by compensating for the length error of the link components; enhancing the stability, the length of the compensated link components is closer to the design value, thereby enhancing the stability of the buffer base; being easy to implement; the method of the present invention can be automatically adjusted by an automatic adjustment device and automatically generate the actual length value of the link components after adjustment; having strong versatility, this method is applicable to various models of multi-link parallel mechanisms and has strong versatility. Brief Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0052] Figure 1 It is a schematic diagram of the assembly and adjustment structure of the buffer base after adjustment in the embodiment of the present invention.

[0053] Figure 2 It is a flowchart of the method provided in the embodiment of the present invention.

[0054] Figure 3 It is a schematic diagram of the coordinate system of the buffer base in the embodiment of the present invention.

[0055] Figure 4 It is a schematic diagram of the structure of the automatic adjustment device provided in the embodiment of the present invention.

[0056] Figure 5 It is an exploded schematic diagram of the structure of the automatic adjustment device provided in the embodiment of the present invention.

[0057] Figure 6 It is a schematic diagram of the gear reduction structure of the automatic adjustment device provided in the embodiment of the present invention.

[0058] Reference Numerals:

[0059] 101, top plate; 102, connecting rod assembly; 103, bottom plate; 104, ball hinge; 105, adjusting pad; 1, movable push rod; 2, guide cylinder; 3, cylinder block; 4, bottom cover; 5, rotating member; 6, reduction mechanism; 61, gear bracket; 62, first gear; 63, first gear set; 64, second gear set; 65, second gear; 66, bearing gland; 67, lock nut; 68, bearing pressing plate; 71, first ball bearing set; 72, second ball bearing set; 73, third ball bearing; 8, servo motor; 9, thrust bearing. Detailed Description of the Embodiments

[0060] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0061] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0062] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0063] In the embodiments of the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0064] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0065] The following will be combined with Figures 1 to 6 to describe the present invention.

[0066] Embodiment

[0067] As shown Figure 2 in the figure, an error adjustment method for the attitude change of a multi-link parallel assembly and adjustment is proposed in an embodiment of the present invention, including the following steps:

[0068] S1: Obtain the designed length of the link assembly and measure the actual length of the link assembly;

[0069] S2: Establish an assembly and adjustment error model for the buffer base;

[0070] S3: Substitute the actual length and the designed length into the assembly and adjustment error model to calculate the compensation amount;

[0071] S4: Record the state of the link assembly before disassembly, remove all link assemblies from the multi-link parallel buffer base, and replace them with an error adjustment compensation device for the attitude change of the multi-link parallel assembly and adjustment with the same quantity;

[0072] S5: According to the compensation amount, implement compensation using the error adjustment compensation device for the attitude change of the multi-link parallel assembly and adjustment, adjust the position of the top plate of the multi-link parallel buffer base, and manufacture an adjustment pad;

[0073] S6: Install the adjustment pad at the top or bottom end of the link assembly, and then reinstall all the link assemblies with the adjustment pads installed back according to the state of the link assembly before disassembly, completing the error adjustment of the attitude change of the multi-link parallel assembly and adjustment.

[0074] In an embodiment of the present invention, in step S1, a high-precision measuring tool is used in the embodiment of the present invention to measure the actual length of each link assembly.

[0075] In an embodiment of the present invention, in step S2, an assembly and adjustment error model for the buffer base is established in the embodiment of the present invention according to the measured actual length and designed length of the link assembly. The specific steps are as follows:

[0076] Step S21: As shown Figure 3 in the figure, establish a fixed coordinate system with the center of the bottom plate of the buffer base as the origin , with the direction from the center of the bottom plate of the buffer base to the edge of the bottom plate of the buffer base as the positive direction of the axis of the fixed coordinate system , with the direction perpendicular to the bottom plate of the buffer base and upward as the positive direction of the axis of the fixed coordinate system . The positive direction of the axis of the fixed coordinate system can form a right-handed coordinate system with the positive directions of the axis and axis of the fixed coordinate system , and define the coordinates of the center of the spherical hinge above the bottom plate of the buffer base; axis of the fixed coordinate system

[0077] A moving coordinate system is established with the center of the top plate of the buffer base as the origin. The positive direction of the x-axis of the moving coordinate system is from the center of the top plate of the buffer base to the edge of the top plate of the buffer base. The positive direction of the y-axis is perpendicular to the top plate of the buffer base and upward. The positive direction of the z-axis can form a right-handed coordinate system with the positive directions of the x-axis and y-axis of the and the coordinates of the center of the ball joint below the top plate of the buffer base are defined. The positive direction of the z-axis can be with the x-axis and the positive direction of the y-axis of the

[0078] Step S22: Since the precision error is mainly composed of the length error of the connecting rod assembly and the clearance error of the ball joint , a dynamic equation of the connecting rod assembly, the clearance error of the ball joint and the pose error of the top plate is established:

[0079]

[0080] Among them,

[0081]

[0082]

[0083]

[0084]

[0085] Among them, is the coordinate of the center of the i th ball joint below the top plate of the buffer base corresponding to the i th connecting rod assembly of the top plate, which is converted from the moving coordinate system to the fixed coordinate system . is the length precision matrix, is the clearance precision matrix, represents the unit vector corresponding to the direction vector i of the th connecting rod assembly, is the coordinate of the center of the ball joint above the i th buffer base bottom plate. i is the serial number of the connecting rod assembly. Among them, i = 1, 2,..., 16. indicate with respect to the moving coordinate system of the origin position vector. Among them, and are not measured, but obtained according to the design principle of the buffer base. is expressed as the moving coordinate system with respect to the fixed coordinate system rotation matrix. is the i th ball hinge center of the buffer base top plate in the moving coordinate system damping vector. In the embodiment of the present invention, is order matrix, is order matrix, is order matrix, is order matrix and is order matrix, , and are order matrix, is order matrix, represents matrix transpose.

[0086] Taking the 16-link buffer base in the embodiment of the present invention as an example, and are substituted into and in, is the rotation matrix, and the length error of the link assembly is the difference between the actual length of the link assembly and the designed length of the link assembly, is a uniform distribution with an upper limit of 0.01 mm and a lower limit of -0.01 mm. Substituting the above variables into the buffer base alignment error model, is obtained.

[0087] Since the calculated is not a zero matrix, according to the perturbation theory, is transformed so that is a zero matrix, and the corresponding length error is obtained, is the compensation amount of the 16-link.

[0088] The above solution can calculate the compensation amount in the alignment error model of the buffer base. The calculated compensation amounts are positive and negative. However, in actual production, the connecting rod assembly can only be extended and cannot be shortened. Therefore, the present invention also provides a device to replace the connecting rod assembly to adjust the length error, accurately determine the compensation amount, and then compensate the connecting rod assembly to achieve the design effect of the buffer base and improve the alignment efficiency.

[0089] According to Figure 4 、 Figure 5 and Figure 6 shown, the error adjustment and compensation device for the attitude change of the multi-link parallel alignment includes: a servo motor 8, a reduction mechanism 6, a rotating member 5, and a movable push rod 1;

[0090] The output end of the servo motor 8 is connected to the bottom end of the reduction mechanism 6;

[0091] The top end of the reduction mechanism 6 is connected to the bottom end of the rotating member 5;

[0092] A groove is provided inside the rotating member 5, and a thread is provided on the inner surface of the groove;

[0093] A thread is provided on the outer surface of the movable push rod 1, and the movable push rod 1 is screwed into the inside of the groove of the rotating member.

[0094] When the servo motor 8 is driven, the rotation speed of the servo motor 8 is reduced by the reduction mechanism 6, and the power is transmitted to the rotating member 5, causing the rotating member 5 to rotate. Through the rotation of the rotating member 5, the thread on the groove inside the rotating member 5 drives the movable push rod 1 to move, enabling the device to adjust the balance of the base.

[0095] The present invention provides an error adjustment and compensation device for the attitude change of the multi-link parallel alignment, further including: a guide cylinder 2, a cylinder block 3, a bottom cover 4, and a thrust bearing 9;

[0096] The rotating member 5 and the movable push rod 1 are installed inside the guide cylinder 2;

[0097] The servo motor 8 and the reduction mechanism 6 are installed inside the cylinder block 3;

[0098] The bottom cover 4 is installed at the bottom of the cylinder block 3;

[0099] The inner ring of the thrust bearing 9 is connected to the rotating member 5;

[0100] The outer ring of the thrust bearing 9 is connected to the cylinder block 3.

[0101] The function of the guide cylinder 2 is to fix the combination of the rotating member 5 and the movable push rod 1, protect the rotating member 5 and the movable push rod 1, and prevent the rotating member 5 and the movable push rod 1 from being damaged by external forces.

[0102] The function of the cylinder block 3 is to facilitate the installation of the servo motor 8, the reduction mechanism 6 and the thrust bearing 9, protect the servo motor 8, the reduction mechanism 6 and the thrust bearing 9, and prevent them from being damaged by external forces.

[0103] The function of the bottom cover 4 is to facilitate the replacement of damaged components when the servo motor 8, the reduction mechanism 6 and the thrust bearing 9 are damaged.

[0104] The function of the thrust bearing 9 is to reduce the rotational friction between the rotating part 5 and the cylinder block 3.

[0105] According to the present invention, the reduction mechanism 6 of an error adjustment and compensation device for attitude change in multi-link parallel assembly and adjustment further includes: a first gear 62, a first gear set 63, a second gear set 64 and a second gear 65;

[0106] The first gear 62, the first gear set 63, the second gear set 64 and the second gear 65 are all installed in the cylinder block 3;

[0107] The servo motor shaft hole of the first gear 62 is connected to the output end of the servo motor 8, and the first gear 62 is used to receive the output from the servo motor 8;

[0108] The teeth of the first gear set 63 are meshed and connected with the teeth of the first gear 62, and the first gear set 63 is used to reduce the output from the servo motor 8;

[0109] The bottom end of the shaft of the second gear set 64 is inserted into the shaft hole of the first gear set 63, the teeth of the second gear set 64 are meshed and connected with the teeth of the second gear 65, and the second gear set 64 is used to reduce the output from the servo motor 8;

[0110] The second gear 65 is used to transmit the input of the servo motor 8 after deceleration to the rotating part 5.

[0111] According to the present invention, the reduction mechanism 6 of an error adjustment and compensation device for attitude change in multi-link parallel assembly and adjustment further includes: a first ball bearing group 71, a second ball bearing group 72, a third ball bearing 73, a bearing gland 66, a lock nut 67, a bearing pressing plate 68 and a gear bracket 61;

[0112] The gear bracket 61 is installed above the servo motor 8; the gear bracket 61 is used to support other components of the reduction mechanism 6.

[0113] The first ball bearing group 71 is installed at the bottom of the gear bracket 61, and the bottom ends of the first gear set 63 and the second gear set 64 are inserted into the inner ring of the first ball bearing group 71;

[0114] The second ball bearing set 72 is installed at the bottom of the bearing gland 66, and the top end of the shaft of the second gear set 64 is inserted into the inner ring of the second ball bearing set 72;

[0115] The third ball bearing 73 is installed at the center of the bearing gland 66, and the top end of the shaft of the second gear 65 is inserted into the inner ring of the third ball bearing 73;

[0116] The lock nut is installed above the inner ring of the third ball bearing 73 and the shaft of the second gear 65, and is used to lock the top end of the shaft of the second gear 65 and the third ball bearing 73;

[0117] The bearing pressing plate 68 is located above the lock nut 67, and the bearing pressing plate 68 is used to press the lock nut 67.

[0118] In the embodiment of the present invention, the first gear set 63 is inserted along the lower end of the second gear set 64 and connected to the second gear set 64 to form an integral body. A set of three first ball bearing sets 71 below the first gear set 63 are installed at the position where the first ball bearing set 71 is installed at the bottom of the gear bracket 61, and the assembly formed by the first gear set 63 and the second gear set 64 is inserted into the hole of the inner ring of the first ball bearing set 71; The three ball bearings, namely the second ball bearing set 72, below the bearing gland 66 are installed at the installation position of the second ball bearing set 72 of the bearing gland 66. The third ball bearing 73 above the bearing gland 66 is installed at the middle position above the bearing gland 66. The upper end shaft of the second gear 65 is inserted into the inner ring hole of the third ball bearing 73 at the middle position and locked through the upper end of the third ball bearing 73 with a lock nut 67. The bearing pressing plate 68 is installed, and the bearing pressing plate 68 presses the lock nut 67 to form a bearing gland assembly; The bearing gland assembly and the gear bracket 61 are assembled. The upper end shaft of the second gear set 64 passes through the inner ring hole of the second ball bearing set 72. The lower end circular positioning hole of the bearing gland 66 fits with the circular positioning shaft at the outer edge of the upper end of the gear bracket 61 to achieve positioning. The first gear 62 is installed on the main shaft of the servo motor 8, and then the servo motor 8 is inserted into the lower end hole of the gear bracket 61 of the reduction mechanism 6. The first gear 62 meshes with the teeth of the first gear set 63, and the first gear set 63 is inserted into the gear bracket 61; The reduction mechanism 6 with the servo motor 8 is inserted into the lower end hole of the cylinder block 3, and the upper end shaft of the second gear 65 passes through the upper end hole of the cylinder block and is connected to the rotating part 5. The bottom cover 4 is installed at the lower end of the cylinder block 3 and is threadedly connected to the cylinder block 3.

[0119] The thrust bearing 9 is inserted into the thrust bearing positioning hole at the upper end of the cylinder block 3, the rotating part 5 is inserted into the inner ring of the thrust bearing 9, the outer ring of the thrust bearing 9 is connected to the cylinder block 3, and the movable push rod 1 is screwed into the rotating part 5. As Figure 5As shown in the figure, there is a guide groove on the side of the movable push rod 1, and a guide piece is provided on the inner side of the top hole of the guide cylinder 2. Align the guide piece of the guide cylinder 2 with the guide groove of the movable push rod 1, install it along the upper end of the rotating member 5, and snap it onto the cylinder block 3.

[0120] 16 automatic adjustment devices are connected in parallel for joint adjustment to ensure that the output attitude accuracy of the buffer base meets the design requirements, determine the compensation amount of the connecting rod assembly 102, and achieve rapid assembly and adjustment of the multi-link buffer base.

[0121] First, remove all the connecting rod assemblies 102 and replace them with error adjustment and compensation devices for multi-link parallel assembly and adjustment of attitude changes with the same quantity.

[0122] Secondly, import the compensation amount calculated in the error model of the buffer base assembly and adjustment into the upper computer. Control the servo motor 8 to rotate through the upper computer. After deceleration by the reduction mechanism 6, it is transmitted to the rotating member 5. The rotation of the rotating member 5 causes the movable push rod 1 to rotate. Due to the guide groove on the side of the movable push rod 1 and the guide piece on the inner side of the top hole of the guide cylinder 2, the rotational motion is converted into a linear motion, enabling the movable push rod 1 to move back and forth. This allows the error adjustment and compensation device for multi-link parallel assembly and adjustment of attitude changes to accurately adjust the buffer base, reducing the error of the buffer base. When the compensation amount is negative, the upper computer controls all the error adjustment and compensation devices for multi-link parallel assembly and adjustment of attitude changes to extend by the same length greater than the compensation amount, and then compensates by reducing the length of the connecting rod assembly 102. The difference between the length of the error adjustment and compensation device for multi-link parallel assembly and adjustment of attitude changes and the actual length of the connecting rod assembly 102 is the thickness of the adjustment pad 105.

[0123] Finally, since the error adjustment and compensation device for multi-link parallel assembly and adjustment of attitude changes cannot replace the connecting rod assembly 102 to provide support and buffering effects for the buffer device. Therefore, reinstall all the connecting rod assemblies, pad the adjustment pad 105 into the connecting rod assembly, and reinstall the top plate 101, connecting rod assembly 102, bottom plate 103, ball hinge 104, and adjustment pad 105 of the buffer device to complete the error adjustment of the multi-link parallel assembly and adjustment of attitude changes. The adjusted buffer base in the embodiment of the present invention is as Figure 1 shown. In the embodiment of the present invention, the adjustment pad 105 is installed at the end of the connecting rod assembly 102.

[0124] The error method and compensation device for multi-link parallel assembly and adjustment of attitude changes adopted in the embodiment of the present invention have the following advantages:

[0125] 1. Improve motion accuracy: By compensating for the length error of the connecting rod assembly, the motion accuracy of the multi-link parallel mechanism can be significantly improved.

[0126] 2. Enhance stability: After compensation, the length of the connecting rod assembly is closer to the design value, thus enhancing the stability of the buffer base.

[0127] 3. Easy to implement: The method of the present invention can be automatically adjusted through an automatic adjustment device, and the actual length value of the adjusted connecting rod assembly can be automatically generated.

[0128] 4. Strong versatility, this method is applicable to various models of multi-link parallel mechanisms and has strong versatility.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for adjusting the error of a multi-link parallel assembly posture change, characterized in that: The following steps are involved: S1: Obtain the design length of the connecting rod assembly and measure the actual length of the connecting rod assembly; S2: Establish the adjustment error model of the buffer base; S21: Establish a fixed coordinate system with the center of the buffer base plate as the origin The coordinate system is the direction from the center of the buffer base bottom plate to the edge of the buffer base bottom plate. of The positive direction of the axis is perpendicular to the bottom plate of the buffer base. of Axis positive direction, of The positive direction of the axis can be of axis, of The positive direction of the axis forms a right-handed coordinate system and defines the coordinates of the ball center of the ball hinge above the bottom plate of the buffer base; Establish a dynamic coordinate system with the center of the buffer base top plate as the origin , the direction from the center of the buffer base top plate to the edge of the buffer base top plate is the moving coordinate system of The positive direction of the axis is perpendicular to the top plate of the buffer base. of Axis positive direction, of The positive direction of the axis can be of axis, of The positive direction of the axis forms a right-hand coordinate system and defines the coordinates of the ball center of the ball hinge under the top plate of the buffer base; S22: Establish the dynamic equations of the connecting rod assembly, ball joint clearance error and top plate posture error: in, is the length precision matrix, is the gap accuracy matrix, is the precision error, is the connecting rod assembly length error, is the clearance error of the ball hinge, and the dynamic equation is the adjustment error model of the buffer base; S3: Substituting the actual length and the designed length into the assembly error model to calculate the compensation amount; S4: Record the state of the connecting rod assembly before disassembly, remove all the connecting rod assemblies from the multi-link parallel buffer base, and replace them with the same number of multi-link parallel assembly posture change error adjustment and compensation devices; S5: according to the compensation amount, using a multi-link parallel mounted posture change error adjustment and compensation device to implement compensation, adjusting the position of the top plate of the multi-link parallel buffer base, and making an adjustment pad; S6: Install the adjustment pad at the top or bottom of the connecting rod assembly, and then reinstall all the connecting rod assemblies with the adjustment pads installed according to the state before the connecting rod assembly was disassembled, so as to complete the error adjustment of the multi-link parallel assembly posture change.

2. The error adjustment method for multi-link parallel assembly posture change according to claim 1, characterized in that: S22 includes: in, For the top plate i The first connecting rod assembly corresponds to the first connecting rod assembly below the top plate of the buffer base. i The coordinates of the center of the spherical hinge By the moving coordinate system Convert to the given coordinate system The coordinates of Expressed as i The direction vector of the connecting rod assembly The corresponding unit vector is For the i The coordinates of the ball center of the ball joint above the bottom plate of the buffer base, i is the connecting rod assembly number, express Relative to the moving coordinate system Origin The position vector of Expressed as the moving coordinate system Relative to the fixed coordinate system The rotation matrix of The top plate of the buffer base i The center of the ball joint is in the moving coordinate system The damping vector, Represents matrix transpose.

3. The error adjustment method for multi-link parallel assembly posture change according to claim 1, characterized in that: In step S3, according to the perturbation theory, , so that becomes a zero matrix, When is a zero matrix, the corresponding is the compensation amount.

4. The error adjustment method for multi-link parallel assembly posture change according to claim 1, characterized in that: Step S5 includes: according to the compensation amount of different connecting rod assemblies, using the upper computer to control the error adjustment and compensation device of the multi-link parallel installation to adjust the posture change, and the difference between the length of the error adjustment and compensation device of the multi-link parallel installation and the actual length of the connecting rod assembly is the thickness of the adjustment pad.

5. The error adjustment method for multi-link parallel assembly posture change according to claim 4, characterized in that: When the compensation amount has a negative value, all the error adjustment compensation devices for the multi-link parallel assembly posture change are first extended by the same length and then adjusted, and the extended length is greater than the compensation amount.

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