Rotary assembly tool for energy absorption box and control method

Abstract

The invention relates to a rotary assembly tool for an energy-absorbing box, which comprises a placing platform connected with a rotary mechanism controlled to rotate, a clamping mechanism for fixing the energy-absorbing box, an assembly mechanism with an assembly end provided with an assembly part, a displacement mechanism connected with the assembly mechanism, a monitoring assembly arranged on the assembly mechanism and an electrical connection controller, an assembly hole is formed in the side face of the energy absorption box, the spatial position relation between the monitoring assembly and the axis of the assembly end is known, edge position parameters of the assembly hole can be measured in real time, the controller drives the displacement mechanism to move the assembly end based on the edge position parameters and the hole size, and the assembly axis and the assembly hole axis are collinear. According to the rotary assembly tool, the problem of hole alignment deviation caused by installation errors or deformation of the energy absorption box is effectively solved, and the assembly precision and the fault tolerance and stability of an automatic assembly system are improved.

Description

Technical Field

[0001] The invention relates to an assembly tool, and in particular to a rotating assembly tool for an energy absorption box and a control method. Background Art

[0002] With the development trend of new energy vehicles, electric logistics vehicles and lightweight vehicles, energy-absorbing structural parts are increasingly used in battery packs, battery compartments, body side beams and other parts. As one of the main buffer structures, energy-absorbing boxes are widely used in automobile collision safety structures because of their good compressive resistance and controllable deformation performance. Energy-absorbing boxes are usually fixedly connected to other structural components by mechanical connection. In order to ensure the overall strength and batch manufacturing efficiency, rotary assembly operations have become an important direction for the development of automated tooling.

[0003] In the prior art, the rotary assembly tooling mainly includes a positioning platform for fixing the energy absorption box, a slewing mechanism for driving the rotation, and an assembly mechanism arranged around the tooling. During the assembly process, the energy absorption box and the standard connector are positioned and fixed by a clamping device, and the assembly mechanism is inserted along the assembly direction to complete the assembly operation. In order to complete the multi-point connection, the assembly platform rotates point by point under the drive of the control system, each time rotating a preset angle to realize the assembly operation of the energy absorption box at different positions. This tooling structure can improve the assembly efficiency and make the connection position more uniform, which helps to improve the overall connection strength and consistency.

[0004] However, in actual assembly, the energy absorption box and the assembly platform are prone to assembly deviation due to positioning accuracy errors, component deformation or structural tolerance accumulation, resulting in offset or difficulty in insertion when the assembly mechanism is aligned with the preset path. Existing tooling mostly relies on preset programs to control the operation of the assembly mechanism, which makes it difficult to achieve high-precision alignment of the complexly distributed assembly holes on the side of the energy absorption box, thus affecting the riveting efficiency and quality. Therefore, a rotary assembly tool is urgently needed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a rotating assembly tool for an energy absorption box, so as to solve the problem in the prior art that when the assembly mechanism performs automated assembly operations on the energy absorption box, the axis of the assembly end and the axis of the assembly hole are offset due to positioning errors or structural deformation of the energy absorption box, thereby improving the assembly accuracy, the success rate of hole alignment and the fault tolerance of the assembly process.

[0006] The technical solution adopted by the present invention to solve the above problem is: a rotating assembly tool for an energy absorption box, wherein an assembly hole is opened on the side of the energy absorption box, and the size parameters of the assembly hole are known quantities, including: The slewing mechanism comprises a first driving end, wherein the first driving end is controlled to rotate around its own axis at a preset angle; A placement platform connected to the first driving end to move synchronously with the first driving end, the placement platform comprising a placement plane for placing the energy absorbing box, and a side surface of the energy absorbing box is perpendicular to the placement plane; A clamping mechanism is arranged on the placement plane, and the clamping mechanism is configured to limit the energy absorption box placed on the placement plane to a preset area when the rotary assembly tool is in a working state; The assembly mechanism comprises an assembly end, on which an assembly part is installed; The displacement mechanism comprises a second driving end for controlled movement, wherein the second driving end is connected to the assembly mechanism to drive the assembly mechanism to move synchronously; A monitoring component is arranged at a preset position on the assembly mechanism, so that the spatial position relationship between the monitoring component and the assembly end axis of the assembly mechanism is limited to a known quantity, and the monitoring component is configured to measure the edge position parameters of the assembly hole on the side of the energy absorption box when the rotary assembly tool is in a working state; A controller is electrically connected to the assembly mechanism, the displacement mechanism and the monitoring component, and the controller is configured to control the movement of the driving end of the displacement mechanism according to the measured edge position parameters of the assembly hole on the side of the energy absorption box and the size parameters of the assembly hole, so that the axis of the assembly end of the assembly mechanism connected to the second driving end is collinear with the axis of the assembly hole on the side of the energy absorption box.

[0007] Preferably, the displacement mechanism comprises: A first moving component, comprising a first moving end that moves in a controlled manner, wherein a moving direction of the first moving end is parallel to the placement plane; a second mobile component connected to the first mobile end to move with the first mobile end, the second mobile component comprising a second mobile end that moves in a controlled manner, the moving direction of the second mobile end being parallel to the placement plane and parallel to the moving direction of the first mobile end; a third mobile component connected to the second mobile end to move with the second mobile end, the third mobile component comprising a third mobile end that moves in a controlled manner, and a moving direction of the third mobile end is perpendicular to the placement plane; A swivel assembly is connected to the third mobile end to move with the third mobile end, the swivel assembly includes a swivel end with controlled rotation, the rotation direction of the swivel end is parallel to the placement plane, and the swivel end is defined as the second driving end.

[0008] Preferably, the monitoring component includes an infrared ranging sensor, which includes an emitting end for emitting an infrared light beam. The light beam emitted by the infrared ranging sensor is parallel to the axis of the assembly end of the assembly mechanism, and the emission direction of the infrared light beam from the emitting end is the same as the direction of the assembly end.

[0009] Preferably, the number of the infrared ranging sensors is two, the two infrared ranging sensors are arranged in parallel, and the center points of the two infrared ranging sensors are both in a first plane, and the first plane is perpendicular to the axis of the transmitting end.

[0010] Preferably, the number of the infrared ranging sensors is at least three, and each of the infrared ranging sensors is arranged at each endpoint of a regular polygon in a one-to-one correspondence, and the number of endpoints of the regular polygon is equal to the number of the infrared ranging sensors, and each of the infrared ranging sensors is arranged in parallel, and the center point of each of the infrared ranging sensors is in a second plane, and the second plane is perpendicular to the axis of the transmitting end.

[0011] Preferably, the clamping mechanism comprises: A first positioning component, disposed on the placement plane, wherein the first positioning component comprises a controlled first limiting end; A second positioning component is arranged on the placement plane, and the second positioning component includes a controlled second limiting end; A third positioning assembly is arranged on the placement plane, and the third positioning assembly includes a controlled third limiting end; Wherein, when the clamping mechanism is in a working state, the first limiting end abuts against a side of the energy absorbing box placed on the placing plane away from the placing platform to limit the movement of the energy absorbing box along a first direction, the second limiting end abuts against a side of the energy absorbing box perpendicular to the placing plane to limit the movement of the energy absorbing box along a second direction, the second direction is perpendicular to the first direction, the third limiting end abuts against a side of the energy absorbing box perpendicular to the placing plane and perpendicular to the second direction to limit the movement of the energy absorbing box along a third direction, the third direction is arranged perpendicularly to the first direction and the second direction.

[0012] In particular, the midpoint of the preset area on the placement plane is defined as the coordinate origin. A control method for the rotary assembly tooling for the energy absorption box includes: Obtaining preset position parameters corresponding to the assembly holes on the side of the energy absorption box; Determine the motion trajectory of the second driving end of the displacement mechanism according to the coordinate origin, the preset position parameters corresponding to the assembly hole, and the preset angle of rotation of the first driving end, so that the axis of the assembly end of the assembly mechanism moves in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box; After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the infrared ranging sensor arranged on the assembly mechanism emits an infrared beam to obtain ranging data generated by the infrared beam irradiating the surface of the energy absorbing box; When the infrared light beam passes through the assembly hole and enters its inner cavity, the distance value measured by the infrared distance measuring sensor changes suddenly, and the edge position parameters of the assembly hole are determined according to the spatial position of the mutation point; The controller determines the offset between the current assembly end axis of the assembly mechanism and the assembly hole axis according to the edge position parameters and the size parameters of the assembly hole, combined with the known spatial coordinate relationship between the monitoring component and the assembly end; According to the offset, the second driving end is controlled to drive the assembly mechanism to perform fine-tuning compensation along the direction of the assembly end axis perpendicular to the side of the energy absorption box and / or around the direction parallel to the assembly end axis, so that the assembly end axis coincides with the assembly hole axis.

[0013] Preferably, the step of determining the motion trajectory of the second driving end of the displacement mechanism according to the coordinate origin, the preset position parameters corresponding to the assembly hole and the preset angle of rotation of the first driving end, and moving the axis of the assembly end of the assembly mechanism in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box comprises: Obtaining a target spatial position of an assembly hole on a side of the energy absorption box in the rotary assembly tooling coordinate system; According to the preset angle of rotation of the first driving end, the preset assembly hole coordinates are transformed to obtain a real-time target position; The second driving end is controlled to move so as to move the axis of the assembly end to a preset vicinity of the axis of the target assembly hole.

[0014] Preferably, after the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the step of emitting an infrared beam by the infrared ranging sensor provided on the assembly mechanism to obtain ranging data generated by the infrared beam irradiating the surface of the energy absorbing box includes: After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the distance values ​​of the assembly end toward the surface of the energy absorbing box are respectively obtained by at least two infrared distance measuring sensors arranged on the assembly mechanism; If the differences between the distance values ​​measured by all the infrared distance measuring sensors are within the equipment error range, it is determined that the axis of the assembly end is perpendicular to the side of the energy absorption box on which the assembly hole is opened.

[0015] Preferably, when the infrared light beam passes through the assembly hole and enters the inner cavity thereof, the distance value measured by the infrared distance measuring sensor changes suddenly, and the step of determining the edge position parameter of the assembly hole according to the spatial position of the mutation point comprises: Determine whether a sudden change value appears in the infrared ranging sensor data, wherein the sudden change value is that the distance value acquired by the infrared ranging sensor changes instantaneously beyond an allowable range; If the mutation value is detected, the mutation point position is marked as the edge of the assembly hole.

[0016] The beneficial effects of the embodiments of the present invention are as follows: 1. Due to the structural design combining the assembly mechanism and the monitoring component, in which the monitoring component is arranged on the assembly mechanism and the spatial position relationship with the axis of the assembly end is a known quantity, the edge position parameters of the assembly hole on the side of the energy absorption box can be measured in real time during the operation of the rotary assembly tooling. Based on the measured edge position parameters and the size parameters of the assembly hole, the controller controls the displacement mechanism to drive the assembly end to achieve precise alignment, so that the axis of the assembly end and the axis of the assembly hole maintain a colinear relationship; therefore, the problem in the prior art that the assembly mechanism cannot be accurately aligned with the assembly hole due to assembly deviation or structural deformation of the energy absorption box is effectively solved, and the problems of assembly insertion failure, hole damage and poor product consistency are avoided; thereby achieving the technical effect of improving assembly accuracy, enhancing assembly fault tolerance and automation adaptability in a complex assembly environment, and ensuring the stability and product quality of the automated assembly process of large quantities of energy absorption boxes.

[0017] 2. Due to the technical means of obtaining the target assembly position by coordinate transformation based on the preset position parameters of the assembly hole and the rotation angle, and combining with multiple infrared ranging sensors on the assembly mechanism to obtain the surface distance data of the energy absorption box, it is judged whether the axis of the assembly end is perpendicular to the assembly surface. At the same time, when the infrared light beam penetrates the inner cavity of the assembly hole, the edge position of the assembly hole is identified by the ranging mutation point, and the offset is calculated and compensated in combination with the hole size parameters. Therefore, the problem in the prior art that the axis of the assembly end is difficult to accurately align with the axis of the assembly hole, insertion failure or damage to the hole edge due to factors such as positioning error, inaccurate posture or structural offset of the energy absorption box is effectively solved; thereby realizing automatic recognition, dynamic correction and high-precision intelligent assembly control effect of the hole, significantly improving the assembly success rate and automation stability of the energy absorption box rotary assembly tooling under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a rotary assembly tool in one embodiment of the present invention.

[0019] Figure 2 It is a schematic structural diagram of an embodiment of the present invention when the assembly mechanism and the displacement mechanism are in a connected state.

[0020] Figure 3 It is a flowchart of a control method for a rotary assembly tool proposed in one embodiment of the present invention.

[0021] Figure 4 It is a flowchart of step S200 of a control method for rotating an assembly tool according to an embodiment of the present invention.

[0022] Figure 5 It is a flowchart of step S300 of a control method for rotating an assembly tool according to an embodiment of the present invention.

[0023] Figure 6 It is a flowchart of step S400 of a control method for rotating an assembly tool according to an embodiment of the present invention.

[0024] Among them: 10, rotating mechanism; 110, first driving end; 20, placing platform; 210, placing plane; 30, clamping mechanism; 310, first positioning component; 311, first limiting end; 320, third positioning component; 321, third limiting end; 40, assembling mechanism; 50, displacement mechanism; 510, first moving component; 511, first moving end; 50, second moving component; 521, second moving end; 530, third moving component; 531, third moving end; 540, rotating component; 541, second driving end; 60, monitoring component; 610, infrared ranging sensor. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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 cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description created by the present application, unless otherwise specified, "multiple" means two or more.

[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0028] See also Figure 1 to Figure 2 In a preferred embodiment of the present application, a rotary assembly tool is provided. The rotary assembly tool is suitable for parts with assembly holes on the side such as energy absorption boxes, and the size parameters of the assembly holes need to be determined before use.

[0029] The above-mentioned rotary assembly tooling includes a rotary structure, a placement platform 20, a clamping mechanism 30, an assembly mechanism 40, a displacement mechanism 50, a monitoring mechanism and a controller, wherein the rotary mechanism 10 includes a first driving end 110, and the first driving end 110 is controlled to rotate around its own axis at a preset angle; the placement platform 20 is connected to the first driving end 110 to move synchronously with the first driving end 110, and the placement platform 20 includes a placement plane 210 for placing an energy absorption box, and the side of the energy absorption box is perpendicular to the placement plane 210; the clamping mechanism 30 is arranged on the placement plane 210, and the clamping mechanism 30 is configured to limit the energy absorption box placed on the placement plane 210 to a preset area when the rotary riveting tooling is in a working state; the assembly mechanism 40 includes an assembly end, and an assembly part is installed at the assembly end; the displacement mechanism 50 includes a second driving end for controlled movement End 541, the second driving end 541 is connected to the assembly mechanism 40 to drive the assembly mechanism 40 to move synchronously; the monitoring component 60 is arranged at a preset position on the assembly mechanism, so that the spatial position relationship between the monitoring component 60 and the axis of the assembly end of the assembly mechanism 40 is limited to a known quantity, and the monitoring component 60 is configured to measure the edge position parameters of the assembly hole on the side of the energy absorption box when the rotary assembly tool is in a working state; the controller is electrically connected to the assembly mechanism 40, the displacement mechanism 50 and the monitoring component 60, and the controller is configured to control the movement of the driving end of the displacement mechanism 50 according to the measured edge position parameters of the assembly hole on the side of the energy absorption box and the size parameters of the assembly hole, so that the axis of the assembly end of the assembly mechanism 40 connected to the second driving end 541 is collinear with the axis of the assembly hole on the side of the energy absorption box.

[0030] In this embodiment, the rotary assembly tool is used to automate the assembly between the energy absorption box and other components, and is particularly suitable for connection processes such as riveting, plugging, and press fitting that require high-precision alignment between the assembly end and the assembly hole. The assembly tool mainly includes: a rotary mechanism 10, a placement platform 20, a clamping mechanism 30, an assembly mechanism 40, a displacement mechanism 50, a monitoring component 60, and a controller, which work together to accurately locate the assembly holes at different positions of the energy absorption box and perform efficient assembly operations.

[0031] The rotating mechanism 10 includes a first driving end 110, which is the output shaft end of the electric rotary servo mechanism. The output shaft is perpendicular to the placement plane 210 and is used to drive the placement platform 20 to rotate around its own axis in a controlled manner to a preset angle. Usually, the angle is stepped in units of 10° to 120° to match the angular distribution of the side holes of different energy absorption boxes.

[0032] The placement platform 20 is arranged at the end surface of the first driving end 110, and is in a rectangular plate shape or a circular or fan-shaped structure. The placement platform 20 includes a horizontally arranged placement plane 210 for placing the energy absorption box, and the assembly surface of the energy absorption box (the side with the assembly hole) is vertical to the placement plane 210, so as to ensure that after the rotation movement, each assembly hole can be accurately positioned in the rotation plane. The platform is made of rigid aluminum alloy or high-strength carbon steel, and the surface can be provided with an anti-skid pad layer.

[0033] The clamping mechanism 30 is arranged on the placement plane 210, and may specifically include a plurality of pneumatic clamps, limit blocks and flexible positioning pins, which are distributed at the edge or corner of the placement platform 20. When the energy absorbing box is placed in a preset area on the placement plane 210 (energy absorbing boxes of the same specification are limited to the same position area on the placement plane 210), the first limit end 311 in the clamping mechanism 30 is used to limit its sliding along the X direction, the second limit end limits its movement along the Y direction, and the third limit end 321 is configured as a push plate that moves vertically (in the Z direction), so that the energy absorbing box is pressed against the placement plane 210 in the Z direction, and the three-way limit jointly ensures the fixed state of the energy absorbing box during the rotation and assembly process. Specifically, in one embodiment, the clamping mechanism 30 includes a first positioning component 310, a second positioning component and a third positioning component 320, wherein the first positioning component 310 is arranged on the placement plane 210, and the first positioning component 310 includes a controlled first limit end 311; the second positioning component is arranged on the placement plane 210, and the second positioning component includes a controlled second limit end; the third positioning component 320 is arranged on the placement plane 210, and the third positioning component 320 includes a controlled third limit end 321; and the clamping mechanism 30 is in a working state. In the state, the first limiting end 311 abuts against a side of the energy absorbing box placed on the placing plane 210 away from the placing platform 20 to limit the movement of the energy absorbing box along the first direction, the second limiting end abuts against a side of the energy absorbing box perpendicular to the placing plane 210 to limit the movement of the energy absorbing box along the second direction, the second direction is perpendicular to the first direction, the third limiting end 321 abuts against a side of the energy absorbing box perpendicular to the placing plane 210 and perpendicular to the second direction to limit the movement of the energy absorbing box along the third direction, the third direction is perpendicular to the first direction and the second direction.

[0034] The assembly mechanism 40 is installed on the second driving end 541. The assembly mechanism 40 can be embodied as a rivet gun, a nail gun, a glue gun, etc., and the assembly end corresponds to the muzzle of the rivet gun, the muzzle of the nail gun, or the muzzle of the glue gun.

[0035] The displacement mechanism 50 includes a second driving end 541 connected to the assembly mechanism 40, and the driving end may be a slide structure or an industrial robot arm with an XYZ three-axis linkage, which is used to drive the assembly mechanism 40 to move precisely in the three-dimensional direction of space. In actual control, the second driving end 541 receives the controller instruction, moves the assembly end according to a predetermined trajectory or a modified trajectory, and aligns its axis with the assembly hole of the energy absorption box to be currently assembled. In one embodiment, the displacement mechanism 50 includes a first displacement component, a second displacement component, a third displacement component and a rotation component 540, wherein the first moving component 510 includes a first moving end 511 for controlled movement, and the moving direction of the first moving end 511 is parallel to the placement plane 210; the second moving component 50 is connected to the first moving end 511 to move with the first moving end 511, and the second moving component 50 includes a second moving end 521 for controlled movement, and the moving direction of the second moving end 521 is parallel to the placement plane 210 and is aligned with the first moving end 511 is parallel to the moving direction of the second moving end 521; the third moving component 530 is connected to the second moving end 521 to move with the second moving end 521, the third moving component 530 includes a third moving end 531 with controlled movement, and the moving direction of the third moving end 531 is perpendicular to the placement plane 210; the rotating component 540 is connected to the third moving end 531 to move with the third moving end 531, the rotating component 540 includes a rotating end with controlled rotation, the rotation direction of the rotating end is parallel to the placement plane 210, and the rotating end is defined as the second driving end 541. The first displacement assembly, the second displacement assembly and the third displacement assembly can be embodied as an XYZ three-axis linkage slide in a specific manner. The motion trajectory of the first movable end 511 of the first displacement assembly is parallel to the X-axis, that is, parallel to the length direction of the energy absorption box restricted on the placement plane 210. The motion trajectory of the second movable end 521 of the second displacement assembly is parallel to the Y-axis, that is, parallel to the width direction of the energy absorption box restricted on the placement plane 210. The plane formed by the X-axis and the Y-axis is parallel to the placement plane 210. The motion trajectory of the third movable end 531 of the third displacement assembly is parallel to the Y-axis, that is, parallel to the height direction of the energy absorption box restricted on the placement plane 210. The rotating component 540 is arranged at the third movable end 531, and the rotating component 540 is a turntable. The second driving end 541 is also the output shaft end of the electric rotation servo mechanism, and the output shaft is arranged perpendicular to the placement plane 210. The assembly mechanism 40 is installed on the second driving end 541, and, in one embodiment, the axis of the assembly end of the assembly mechanism 40 is arranged perpendicular to the axis of the second driving end 541, that is, the axis of the assembly end is parallel to the placement plane 210, so that the axis of the assembly end can move and change position on the plane.

[0036] The monitoring assembly 60 is fixedly mounted at a preset position on the assembly mechanism 40, and the spatial position relationship between its center and the central axis of the assembly end is a fixed known quantity, so as to provide a correction amount for aligning the axis of the assembly end with the axis of the assembly hole.

[0037] During use, after the energy absorbing box is fixed on the placement platform 20, the controller rotates the placement platform 20 to a specified angle through a preset program so that the current target assembly hole faces the assembly end. Then, the controller controls the displacement mechanism 50 to drive the assembly mechanism 40 to move to the vicinity of the estimated position of the target assembly hole, and the monitoring component 60 is activated to measure the edge position of the assembly hole. The controller infers the center position of the assembly hole based on the edge position of the assembly hole and the standard size of the assembly hole.

[0038] Based on the measured edge position parameters, the preset assembly hole size, and the relative coordinates between the detection component and the assembly end, the controller calculates the spatial offset between the assembly end axis and the assembly hole axis in real time, and further controls the second drive end 541 to adjust the position and posture of the assembly mechanism 40 to achieve the colinear alignment of the assembly end axis and the assembly hole axis. After the alignment is completed, the assembly mechanism 40 performs the assembly operation to complete the connection of an assembly point. After that, the slewing mechanism 10 drives the placement platform 20 to rotate to the next assembly hole position, and repeats the above process until all hole positions are assembled.

[0039] This technical solution is applicable to the fields of vehicle body structure assembly, power battery box connector fixation, distributed installation of energy absorbers, etc. It is adaptable to industrial automation environments, has strong compatibility, and can cope with actual errors such as slight differences in multiple batches of energy absorption boxes and slight warping.

[0040] The rotary assembly tool disclosed in this embodiment improves the assembly alignment accuracy and automated alignment capability by adopting a monitoring component 60, a combination of assembly posture verification and dynamic trajectory compensation, and effectively solves the hole offset problem caused by structural tolerance and error accumulation. It is suitable for assembly scenarios with high requirements for connection accuracy and multi-hole eccentric distribution, and has significant advantages such as high accuracy, fast speed, large error tolerance, and high automation level.

[0041] Furthermore, the monitoring component 60 includes an infrared distance sensor 610, and the infrared distance sensor 610 includes a transmitting end for emitting an infrared light beam. The light beam emitted by the infrared distance sensor 610 is parallel to the axis of the assembly end of the assembly mechanism 40, and the emission direction of the infrared light beam of the transmitting end is the same as the direction of the assembly end. In addition, in order to make the axis of the assembly end perpendicular to the side of the energy absorption box with the assembly hole before assembly, in one embodiment, the number of the infrared distance sensors 610 is two, the two infrared distance sensors 610 are arranged in parallel, and the center points of the two infrared distance sensors 610 are both in the first plane, and the first plane is perpendicular to the axis of the transmitting end.

[0042] In this embodiment, the monitoring component 60 is used to perform spatial recognition and posture verification on the energy absorption box assembly hole before the assembly operation. Its core structure is an infrared distance sensor 610 component arranged on the assembly mechanism 40.

[0043] The monitoring assembly 60 includes at least two infrared distance measuring sensors 610 (optionally a TOF sensor, a laser triangulation distance measuring device or an infrared echo distance measuring device), which can be fixed to the outer bracket of the assembly end by bolt installation or a quick release slot, and are preferably arranged symmetrically. The transmitting ends of the two infrared distance measuring sensors 610 are arranged parallel to each other, respectively located on both sides of the assembly end, and their center points are coplanar and both located in a geometric plane called a "first plane", which is perpendicular to the central axis of the assembly end, so as to ensure that the distances of the two infrared distance measuring sensors to the same vertical plane are equal.

[0044] Each infrared distance sensor 610 includes an infrared light emitting end (facing the same direction as the assembly end), an optical receiver and an integrated electronic control signal processing unit. The infrared light beam is strictly parallel to the axis of the assembly end to ensure that the distance information obtained is comparable and consistent in direction. The infrared distance sensor 610 can be connected to the controller via a shielded cable, and the signal is transmitted via a CAN bus or serial communication. In addition, the spacing between the two infrared distance sensors 610 can be selected to be 20 mm to 50 mm, and the specific value needs to be set according to the structural size of the assembly end and the diameter of the assembly hole.

[0045] Before assembly, the controller drives the assembly mechanism 40 to move to the vicinity of the hole to be assembled according to the preset coordinates of the target assembly hole. The infrared ranging sensor 610 is immediately activated and continuously emits infrared beams to obtain ranging data corresponding to the surface of the energy absorption box. Then, the controller compares the ranging values ​​obtained by the two sensors at the same time. If the difference Δd is less than the set error threshold (for example, ±1mm), it is judged that the axis of the assembly end is perpendicular to the normal direction of the side of the energy absorption box. If Δd exceeds the limit, it is considered that the current posture is skewed, and the controller issues an adjustment instruction to fine-tune the posture of the assembly end through the rotating component 540 until the verticality judgment is met.

[0046] When the axis is vertically aligned, the infrared distance sensor 610 continues to work to obtain the edge position of the assembly hole. When the infrared beam enters the assembly hole, its distance data will change from near to far. The system captures the position of the mutation point to determine the edge of the assembly hole, and then combines the known aperture parameters to infer the coordinates of the hole center.

[0047] Finally, the controller completes the correction of the position and posture of the assembly end so that its central axis is collinear with the axis of the hole to be assembled.

[0048] The key links in the specific implementation process include: Posture judgment: Whether the distance values ​​of multiple sensors are consistent is used as the basis for judging whether the assembly end is vertical.

[0049] Mutation recognition, monitoring the mutation points of the distance curve, is used to detect the hole edge.

[0050] Center positioning, calculates the center position based on the known calibration relationship and aperture information between the two sensors and the assembly end.

[0051] Fine-tuning control: If deviation exists, the controller achieves precise alignment through the combined compensation of the rotation component 540 and the displacement component.

[0052] This process is a closed-loop control logic. Each posture and position verification is dynamically adjusted based on real-time measurement data. There is no need to rely on open control that only relies on preset coordinates, which greatly improves the adaptability of the assembly tooling.

[0053] In this embodiment, due to the use of a structural arrangement based on two parallel infrared distance measuring sensors 610, and keeping the infrared beam parallel to the axis of the assembly end, the assembly end is judged to be perpendicular to the assembly surface of the energy absorption box by comparing the change in distance data, and further the edge recognition and center positioning of the assembly hole are realized; therefore, the problem of the axis of the assembly end deviating from the axis of the assembly hole due to the spatial deviation or deformation of the target part in the existing automatic assembly system is effectively solved, especially the drawbacks of the traditional vision system that is interfered by light and reflection are avoided. In addition, a non-contact, fast, real-time, closed-loop controlled high-precision hole alignment system is realized, which significantly improves the fault tolerance, stability and production efficiency of the assembly automation system, and is suitable for automatic assembly scenarios of various types of energy absorption structures.

[0054] It should be noted that, in the actual operation process, although the assembly hole of the energy absorption box may deviate from the preset target position due to positioning error, manufacturing tolerance and other factors, since the deviation is usually small, in the process of the displacement mechanism 50 driving the assembly mechanism 40 to gradually approach the target position, the infrared beam is still very likely to pass through the edge area of ​​the assembly hole and shoot into the hole, thereby triggering the mutation point recognition. In actual engineering, the preset assembly hole position comes from the CAD model or manual calibration, and the error is usually within ±2mm. Moreover, the controller will not position the assembly end axis to align only with an absolute point, but move it to the area near the point (buffer zone). For example, in a space cylindrical area with a diameter of 2mm to 3mm, the diameter of the infrared beam or the ranging field of view usually has a certain diffusion angle (for example, ±1°). Therefore, as long as the preset path is not too far away, the infrared beam is very likely to scan the edge of the assembly hole and complete the mutation judgment. In addition, when the controller drives the assembly end to approach the assembly hole, it is not in place in one step, but multiple sampling is performed during the approaching process. Every time it moves a certain distance (for example, 0.5mm to 1mm), the infrared ranging will be triggered once and the data will be recorded. In the process of approaching, even if the infrared beam is not aligned with the center of the assembly hole, a mutation signal will still be detected when the infrared beam path sweeps over the edge of the assembly hole. Moreover, the edge area is the place where ranging mutations are most likely to occur. When the infrared beam hits a solid surface, it returns a short distance. Once the beam enters a cavity, it returns a long distance or no echo. This mutation point is most likely to appear at the moment when the beam cuts into the cavity from the solid edge. Therefore, "scanning the edge" is equivalent to "triggering judgment." Therefore, under the conditions of reasonable control of the preset path accuracy and controlled error range, the infrared ranging beam will almost certainly pass through or approach the edge area of ​​the assembly hole during the process of the displacement mechanism 50 approaching the assembly hole, thereby entering the hole to achieve the capture and judgment of ranging mutations.

[0055] Furthermore, in some other embodiments, the number of the infrared ranging sensors 610 is at least three, each of the infrared ranging sensors is arranged at each endpoint of a regular polygon in a one-to-one correspondence, and the number of endpoints of the regular polygon is equal to the number of the infrared ranging sensors 610, each of the infrared ranging sensors 610 is arranged in parallel, and the center point of each of the infrared ranging sensors 610 is in a second plane, and the second plane is perpendicular to the axis of the transmitting end.

[0056] In a further optimization scheme of the present embodiment, the number of infrared ranging sensors 610 provided in the monitoring component 60 is three or more, and each infrared ranging sensor 610 is arranged at each vertex of the regular polygon in a one-to-one correspondence. For example, when the number of sensors is 3, they are arranged at the three endpoints of an equilateral triangle; if there are 4 sensors, they are arranged at the four corners of a square, and so on.

[0057] The center points of the infrared distance measuring sensors 610 are all located in a plane called the "second plane", which is perpendicular to the central axis of the assembly end, that is, perpendicular to the emission direction of the infrared distance measuring sensor 610. The emission directions of the light beams of all sensors are parallel to the axis of the assembly end and are oriented in the same direction as the assembly action, ensuring that an array of equally spaced distance measuring planes is formed in three-dimensional space.

[0058] Each sensor is independently mounted on the corresponding mounting bracket on the assembly mechanism 40, and the bracket can be fixed to the end support frame of the assembly mechanism 40 by bolts, buckles or modular rails, which is convenient for replacement and calibration. The installation spacing is set according to the side length of the regular polygon, and the recommended side length is 10mm to 25mm, which can be adjusted according to the size of the assembly parts and the space margin.

[0059] Each infrared ranging sensor 610 is connected to the main controller by an independent cable, and the signal is transmitted in parallel through the CAN bus or RS485 bus to ensure high-speed real-time synchronous sampling, and cooperate with the multi-channel A / D module for unified data processing.

[0060] In this embodiment, multiple infrared distance measuring sensors 610 are provided. Compared with the axis vertical verification and edge recognition scheme realized by dual sensors, the regular polygon array formed by multiple infrared distance measuring sensors 610 in this embodiment can realize a wider range scanning and posture determination of the assembly hole and the surrounding space. The working principle is as follows: First, the controller calculates the distance between each point and the assembly surface of the energy absorption box according to the ranging values ​​returned in real time by multiple infrared ranging sensors.

[0061] Then, based on the point set consisting of three or more ranging points, the controller uses mathematical methods such as the least squares method to fit an "actual assembly surface plane".

[0062] Then, the angle between the normal vector of the fitting plane and the direction vector of the axis of the assembly end is calculated. If the angle is less than the set tolerance (such as 1°), it is considered that the axis of the assembly end is perpendicular to the assembly surface.

[0063] Afterwards, during the gradual approach process, multiple sensors simultaneously detect whether there is a distance measurement mutation point. If any distance measurement value changes suddenly, the "edge judgment logic" is triggered. The spatial position of the center point of the assembly hole is reversed by combining the coordinate positions of multiple mutation points and the standard size of the assembly hole.

[0064] Finally, the controller controls the displacement mechanism 50 and the rotary assembly 540 to move in conjunction with each other, so that the axis of the assembly end is aligned with the axis of the assembly hole.

[0065] Among them, three points are used to determine a plane, and the normal line of the assembly surface is judged by fitting the relationship between the "measurement point and the assembly surface". Using four or more points can form an overdetermined system, and the system can still operate fault-tolerantly when the signal of an individual sensor is abnormal. The robustness of the hole center judgment is further enhanced by fitting the hole edge shape through the joint position of multiple mutations. In addition, the ranging values ​​of all infrared ranging sensors are sampled simultaneously in the same cycle to ensure the real-time and consistency of the judgment logic.

[0066] In this embodiment, a multi-point infrared ranging sensor 610 array arrangement structure is adopted, and the emission direction of each sensor is unified and kept parallel to the axis direction of the assembly end, and all center points are coplanar, forming a stable and resolvable three-dimensional ranging array structure; therefore, the problem of inaccurate judgment and poor adaptability in the existing two-point hole alignment system when facing inclined assembly surfaces or large-range offset hole positions is effectively solved; thereby realizing a three-dimensional space posture recognition and assembly hole center positioning system with higher dimensions, stronger fault tolerance and more reliable redundant mechanism, improving the adaptability of automatic assembly equipment to energy absorption box structures with complex morphology, and significantly improving assembly efficiency and accuracy.

[0067] Among them, "Based on a point set consisting of three or more ranging points, the controller uses mathematical methods such as the least squares method to fit an "actual assembly surface plane", and calculates the angle between the normal vector of the fitting plane and the direction vector of the assembly end axis. If the angle is less than the set tolerance (such as 1°), it is considered that the assembly end axis is perpendicular to the assembly surface" is as follows: Multiple infrared distance measuring sensors 610 have the same emission direction (parallel to the axis of the assembly end). When they measure the distance values ​​of different points on the assembly surface of the energy absorption box, it is equivalent to obtaining the coordinates of a set of points in three-dimensional space. If these points fall on a plane (ideal case), the "actual plane equation" of this assembly surface can be fitted. After fitting, the normal vector of the plane can be calculated, and then the angle between the normal vector and the direction vector of the axis of the assembly end is calculated. If the angle is close to 0 (less than a threshold, such as 1°), it can be determined that the orientation of the assembly end is "perpendicular" to the normal vector of the assembly surface, which meets the assembly conditions.

[0068] The logic of obtaining coordinate data is as follows: Assume that there are three infrared distance measuring sensors 610 in the system, named A, B, and C, arranged in an equilateral triangle. The coordinates of the installation position of each infrared distance measuring sensor 610 (in the assembly mechanism 40 coordinate system) are known and are set as: A = (x 1 ,y 1 , z 1 )、B=(x 2 ,y 2 , z 2 ) and C = (x 3 ,y 3 , z 3 The distances they measured are d 1 d 2 and d 3 (The distance measurement direction is the direction of the X-axis or Y-axis toward the side of the energy absorption box, that is, the direction of the assembly end.) The spatial coordinates of each sensor irradiating the surface of the energy absorption box are: P 1 =(x 1 +d 1 ,y 1 , z 1 )、P 2 =(x 2 +d 2 ,y 2 , z 2 )、P 3 =(x 3 +d 3 ,y 3 , z 3 ).

[0069] Given three points P 1 , P 2 , P 3 , the plane normal vector n can be found by the following steps: V 1 =P 2 -P 1 ; V 2 =P 3 -P 1; n = V 1 ×V 2 .

[0070] Normalize the normal vector n = (a, b, c) to be the unit normal vector of the plane.

[0071] Assume that the direction vector of the center axis of the assembly end is d=(1, 0, 0). (Along the X axis)

[0072] Calculate the angle: cos(θ)=(n·d) / (‖n‖‖d‖); if θ≈0° (the allowable deviation range is usually between 0° and 1°), it is judged as "perpendicular to the assembly surface", otherwise, the posture of the assembly end needs to be adjusted.

[0073] See also Figure 3 In order to achieve high-precision hole assembly under the position error of the energy absorption box assembly hole, in one embodiment, a rotary assembly tool control method based on infrared ranging feedback is proposed. The method relies on the linkage operation of the rotary mechanism 10, the displacement mechanism 50 and the monitoring component 60 to achieve dynamic adjustment of the assembly hole position and posture at the assembly end, and has high fault tolerance and real-time performance. The midpoint of the preset area on the placement plane 210 is defined as the coordinate origin, and the control method specifically includes the following steps: Step S100: obtaining preset position parameters corresponding to the assembly holes on the side of the energy absorption box; Step S200: determining the motion trajectory of the second driving end 541 of the displacement mechanism 50 according to the coordinate origin, the preset position parameters corresponding to the assembly hole, and the preset angle of rotation of the first driving end 110, so that the axis of the assembly end of the assembly mechanism 40 moves in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box; Step S300: after the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the infrared ranging sensor 610 disposed on the assembly mechanism 40 emits an infrared beam to obtain ranging data generated by the infrared beam irradiating the surface of the energy absorbing box; Step S400: When the infrared light beam passes through the assembly hole and enters its inner cavity, the distance value measured by the infrared distance measuring sensor 610 changes suddenly, and the edge position parameters of the assembly hole are determined according to the spatial position of the mutation point; Step S500: The controller determines the offset between the current assembly end axis of the assembly mechanism 40 and the assembly hole axis according to the edge position parameters and the size parameters of the assembly hole, combined with the known spatial coordinate relationship between the monitoring component 60 and the assembly end; Step S600: According to the offset, control the second driving end 541 to drive the assembly mechanism 40 to perform fine-tuning compensation along the direction of the assembly end axis perpendicular to the side of the energy absorption box and / or around the direction parallel to the assembly end axis, so that the assembly end axis coincides with the assembly hole axis.

[0074] Among them, with respect to "step S100 to obtain the preset position parameters corresponding to the assembly holes on the side of the energy absorption box", during the system initialization phase, the controller sets the midpoint of the preset area on the rotating assembly tool placement plane 210 as the origin of the spatial coordinates, and establishes an XYZ three-dimensional coordinate system, in which the Z axis is perpendicular to the assembly surface, and is used to describe the thrust direction of the assembly end. The controller then calls the structural modeling data of the energy absorption box, obtains the spatial position coordinates, normal direction and aperture information of each assembly hole, and loads them into the cache table in structural order to form a target assembly information table, providing a unified geometric basis and data interface for subsequent path control, infrared ranging judgment, attitude verification and assembly compensation. Step S100 is described in detail as follows: The purpose of this step is to provide accurate target positioning data for the subsequent control of the spatial motion trajectory of the assembly end. By establishing a unified coordinate system and loading the preset assembly hole spatial parameters, the data calculation of the entire assembly process is ensured to have a unified reference and convertibility.

[0075] Step S110: Establish a unified coordinate system. In the system initialization stage, the controller performs spatial calibration on the placement platform 20 where the energy absorption box is placed in the rotating assembly tooling, sets the center point of the preset area on the placement plane 210 (the center point of the placement plane 210) as the coordinate origin (0, 0, 0), and establishes the following three-dimensional space coordinate system: The Z-axis direction is perpendicular to the placement plane 210 and points to the forward direction of the assembly end (usually the "downward pressing direction"). The X-axis direction is consistent with the length direction of the placement platform 20. The Y-axis direction is consistent with the width direction of the placement platform 20 and is perpendicular to the X-axis. This coordinate system is used as the "assembly reference coordinate system" in the system. The subsequent assembly hole positions and the assembly mechanism 40 trajectory are all referenced by this coordinate system.

[0076] Step S120: Importing the assembly hole space parameters. The controller obtains or reads the theoretical modeling data of the energy absorption box structure through the parameters or models, including: The number or ID of all mounting holes of the crash box.

[0077] The spatial position coordinates of each assembly hole in the three-dimensional model, that is, the (X, Y, Z) value relative to the coordinate origin.

[0078] The hole size parameters of each mounting hole.

[0079] The normal direction vector of each assembly hole is used to determine the assembly direction.

[0080] The initial posture (angle) parameters of the energy absorption box after it is installed as a whole on the assembly fixture, including information such as the rotation angle (around the Z axis) or the tilt angle (used for subsequent coordinate transformation calculations).

[0081] The above data can come from the hole position data table converted from the CAD model, the position template preset in the intelligent calibration system, the hole position table (such as Excel, database) manually input or set by the user. These data are formatted and stored in the controller as part of the target assembly instruction set.

[0082] S130: Spatial data caching and binding assembly strategy. The controller classifies and caches all acquired assembly hole position information, including the hole ID, X coordinate, Y coordinate, Z coordinate, aperture, normal direction (i, j, k), structural surface and initial angle of each hole. The system then logically binds each hole position data with the corresponding assembly sequence, assembly tool type used, and assembly mode, and generates a hole and process mapping relationship table to provide a matching basis for subsequent step-by-step control (such as rotation angle, assembly sequence, and assembly path).

[0083] The key technical points in this step are as follows: Selection of reference origin. By setting a unified origin and coordinate system, the ambiguity of the coordinate system caused by the geometric shape of the energy absorption box or the clamping position can be eliminated, which is convenient for subsequent rotation transformation and space compensation calculation.

[0084] The spatial consistency of the preset position parameters takes the coordinate system as a unified reference, and the assembly hole positions of all energy absorption boxes can be uniformly processed, dynamically matched and vector transformed.

[0085] In addition, this step supports loading dynamic hole position tables for energy absorption boxes of different specifications. The controller can switch the target hole position parameters according to the work order or system identification code, which is highly flexible.

[0086] It should be noted that step S100 is the first stage of the entire control process, providing an input reference for the path planning of step S200 and the infrared ranging start of step S300. The target coordinates of the assembly holes obtained after the completion of S100 will serve as the spatial comparison basis for the subsequent posture judgment and deviation compensation algorithm. If this step is skipped, the system will not be able to build a dynamic matching mechanism, and the assembly end will not be able to accurately align with the target hole position.

[0087] See also Figure 4, with respect to "step S200 determines the motion trajectory of the second drive end 541 of the displacement mechanism 50 according to the coordinate origin, the preset position parameters corresponding to the assembly hole and the preset angle of rotation of the first drive end 110, so that the axis of the assembly end of the assembly mechanism 40 moves in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box", the controller obtains the target coordinates of the center of the real-time assembly hole through a three-dimensional space transformation method based on the coordinate origin and the preset spatial position parameters of the assembly hole, combined with the current rotation angle of the first drive end 110. Then, the target trajectory is generated, and the displacement mechanism 50 connected to the second drive end 541 is controlled to operate, so that the assembly end of the assembly mechanism 40 moves to the buffer work area in the center of the assembly hole according to the predetermined path, completing the transition positioning from the initial position to the precision assembly area.

[0088] Step S210: obtaining the target spatial position of the assembly hole on the side of the energy absorption box in the rotary assembly tooling coordinate system; Step S220: transforming the preset assembly hole coordinates according to the preset angle of current rotation of the first driving end 110 to obtain a real-time target position; Step S230: Control the second driving end 541 to move so as to move the axis of the assembly end to a preset vicinity of the axis of the target assembly hole.

[0089] Wherein, step S210 obtains the target spatial position of the assembly hole on the side of the energy absorption box in the rotating assembly tooling coordinate system as follows: First, read the spatial position data of the assembly hole cached by the controller, that is, extract the center coordinates of the current assembly hole from the target hole position parameter table established in step S100: The original target coordinates (relative coordinate origin) are This coordinate is the theoretical center point of the assembly hole of the energy absorption box when it is in the "unrotated" state.

[0090] Step S220 transforms the preset assembly hole coordinates according to the preset angle of rotation of the first driving end 110 to obtain a real-time target position. The details are as follows: Since the energy absorption box is positioned by rotating the rotating mechanism 10, there is a rotation difference between the actual current hole position and the theoretical value. The controller obtains the current rotation angle of the first driving end 110 , and perform a two-dimensional plane rotation transformation to The coordinate point rotates around the coordinate origin (Z axis) Degrees, get real-time target position .

[0091] The calculation formula is: .

[0092] The z-axis direction remains unchanged because the rotation is only performed in the plane of the platform.

[0093] Step S230: Control the second driving end 541 to move so as to move the axis of the assembly end to a preset vicinity of the axis of the target assembly hole, as follows: According to the transformed target coordinates, the controller generates instructions to drive the second driving end 541 to move the assembly mechanism 40 from the current position to the vicinity, that is, the "buffered working area" of the target hole axis according to the shortest path strategy.

[0094] The system defaults this "buffer zone" to a cylindrical area with a radius of 2mm to 3mm at the center. The assembly end can trigger infrared ranging judgment within this area.

[0095] In step S200, the key technical points include: Precision control of spatial coordinate transformation: The angle reading should be the encoder or servo system feedback value with an accuracy of at least 0.1° to ensure the accuracy of the displacement path calculation.

[0096] Path planning logic: The moving path preferably adopts a three-axis straight-line segmented composite path (non-curved trajectory) to simplify the control algorithm and improve motion stability.

[0097] Buffer strategy setting: The introduction of the "buffered working area" mechanism can improve the system's tolerance to assembly hole position tolerance and energy absorption box installation deviation, ensuring that the infrared ranging link successfully enters the working window.

[0098] It should be noted that step S200 depends on the original coordinate data output by S100, depends on the current rotation angle fed back by the rotary mechanism 10, and is a prerequisite for the subsequent step S300 of "the assembly end approaches the assembly hole and triggers infrared ranging".

[0099] See also Figure 5 After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole in step S300, the infrared ranging sensor 610 disposed on the assembly mechanism 40 emits an infrared beam, and the ranging data generated by the infrared beam irradiating the surface of the energy absorbing box is obtained, including: Step S310: after the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the distance values ​​of the assembly end toward the surface of the energy absorbing box are respectively obtained by at least two infrared distance measuring sensors 610 arranged on the assembly mechanism 40; Step S320: If the differences between the distance values ​​measured by all the infrared distance measuring sensors 610 are within the equipment error range, it is determined that the axis of the assembly end is perpendicular to the side of the energy absorption box having the assembly hole.

[0100] The purpose of step S300 is to obtain the geometric state information of the surface where the energy absorption box assembly hole is located in real time through infrared ranging technology when the assembly end approaches the target assembly hole position, preliminarily complete the judgment of the posture flatness (verticality), and provide a data basis for subsequent hole edge identification and position compensation. In step S300, after the controller detects that the assembly end enters the area near the axis of the target assembly hole, it starts the multiple infrared ranging sensors 610 installed on the assembly mechanism 40, emits infrared beams along the axis direction of the assembly end, and collects the real-time ranging data generated by the infrared beam irradiated to the assembly surface of the energy absorption box. The controller makes a difference judgment on each ranging value. If the difference of the distance values ​​measured by all sensors is within the allowable range of equipment error, it is judged that the axis of the assembly end is perpendicular to the normal direction of the side of the energy absorption box; if the ranging difference exceeds the tolerance range, the assembly mechanism 40 is controlled to rotate the assembly 540 to perform fine-tuning compensation, and repeat the ranging judgment process to form a closed-loop attitude control.

[0101] In step S310, after the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the distance values ​​of the assembly end toward the surface of the energy absorption box are respectively obtained by at least two infrared distance measuring sensors 610 arranged on the assembly mechanism 40, as follows: After detecting that the assembly end has entered the aforementioned "target buffer work area", the controller starts a plurality of infrared distance measuring sensors 610 (at least two, preferably three or four, arranged symmetrically around the assembly end) disposed at the end of the assembly mechanism 40. The emission directions of these infrared distance measuring sensors 610 are all parallel to the axis of the assembly end, and infrared beams are emitted along the predetermined assembly direction (X axis or Y axis). The controller collects the distance values ​​(such as d 1 , d 2 , d 3 ...), each sensor corresponds to a fixed spatial installation coordinate (calibrated by mechanical design).

[0102] In step S320, if the differences between the distance values ​​measured by all the infrared distance measuring sensors 610 are within the equipment error range, it is determined that the axis of the assembly end is perpendicular to the side of the energy absorption box having the assembly hole, as follows: The controller compares the above multiple distance measurement values, calculates the difference Δd between each of them, and determines whether the set vertical error threshold (such as ±1mm) is met.

[0103] If the difference in the distance measurement values ​​of all sensors is less than or equal to the threshold, it means that the axis of the assembly end is perpendicular or approximately perpendicular to the normal direction of the energy absorption box surface, and the next step of "hole edge mutation identification" can be entered; If the Δd between a pair of sensors exceeds the tolerance, it means that there is a deviation between the assembly end posture and the assembly surface. The controller issues a correction instruction, adjusts the assembly end posture (such as slight rotation) through the rotary component 540, and resamples for judgment to form a closed-loop adjustment.

[0104] The key technical points of step S300 are as follows: A non-contact pre-judgment mechanism is adopted. Compared with the traditional hard alignment method, infrared ranging can realize the ability to judge "whether it is vertical" without contact, reducing the risk of mis-insertion.

[0105] Multi-point parallel acquisition. Using multiple infrared distance measuring sensors 610, the height value of the energy absorption box surface can be read at different points at the same time, and the spatial "slope perception" of the assembly surface can be formed through geometric fitting.

[0106] Angle error inversion: When the difference is too large, the deflection direction and angle can be inferred through simple geometric methods, and the rotation component 540 can be controlled to compensate, thereby improving the attitude adaptability.

[0107] Moreover, this step is the premise of step S400 (mutation identification). If the verticality judgment is not passed, the next step of hole edge capture is not allowed, and if the posture error continues to fail to meet the requirements, an "assembly abnormality alarm" can be issued to prevent erroneous operations.

[0108] See also Figure 6 , step S400 After completing the vertical posture calibration of the assembly end, the controller starts the infrared ranging mutation recognition program, reads the data stream returned by the infrared ranging sensor 610 in real time, and determines whether there is a situation where the distance value suddenly changes in a unit time. If it is detected that the change amplitude of a certain ranging data exceeds the preset threshold (for example, 50mm), it is considered that the infrared light beam has penetrated the assembly hole and entered its inner cavity area. The system marks the position coordinates corresponding to the mutation point as the edge position parameter of the assembly hole. The edge position point is subsequently used to calculate the center axis of the assembly hole to achieve precise control of the hole. The purpose of this step is to identify the edge position point of the assembly hole through the distance mutation phenomenon when the infrared light beam penetrates the assembly hole and enters its internal cavity after the assembly end has been adjusted to a perpendicular state to the assembly surface of the energy absorption box, and to use it for subsequent center position fitting and error compensation.

[0109] Step S400: When the infrared light beam passes through the assembly hole and enters its inner cavity, the distance value measured by the infrared distance measuring sensor 610 changes suddenly. Determining the edge position parameters of the assembly hole according to the spatial position of the mutation point includes: S410 determines whether a sudden change value appears in the data of the infrared distance measuring sensor 610, wherein the sudden change value is that the distance value acquired by the infrared distance measuring sensor 610 changes instantaneously beyond the allowable range, as follows: When the assembly end maintains the current static or slow advancing state, the controller continuously reads the distance data sequence d(t) of each infrared ranging sensor 610 and executes the dynamic change rate judgment algorithm: Set mutation judgment threshold , such as 50mm; Determine whether the difference between the current sampling value and the previous sampling value satisfies: .

[0110] If the mutation condition is met, the distance measurement value and the spatial coordinates of the assembly mechanism 40 corresponding to the time point are recorded and marked as the "mutation point". This mutation represents that the infrared beam suddenly passes from the solid area of ​​the assembly surface to the internal cavity of the assembly hole, forming a long distance or echo disappearance state, which is the direct basis for the edge identification of the assembly hole.

[0111] If the mutation value is detected in S420, the mutation point position is marked as the edge of the assembly hole, as follows: The system marks the spatial coordinates of the mutation sampling point as the edge point of the assembly hole and saves its three-dimensional coordinates in preparation for the subsequent center axis calculation.

[0112] If multiple infrared ranging sensors have mutation phenomena, the coordinates of all mutation points are combined to form an edge point set; Optionally, these mutation points are fitted as an arc edge or the aperture symmetry center is inferred through geometric analysis.

[0113] The key technical points of step S400 include: The infrared ranging will trigger the judgment when it becomes no echo or greater than 50mm instantly after entering the hole cavity, which is greater than the set threshold.

[0114] In addition, in order to ensure the first-time response sampling frequency and mutation positioning accuracy that can capture the mutation point, high-frequency sampling (such as 50Hz or above) can be set through the controller to improve the accuracy of edge positioning (error less than 0.5mm).

[0115] Furthermore, the collaborative identification of mutation points by multiple sensors can be used to filter out occasional measurement errors (such as local reflections) and improve recognition accuracy.

[0116] Output of step S400 It is a direct input to the "offset calculation" of S500. If the mutation point cannot be identified, the controller can issue an "unconfirmed hole position" alarm and suspend the assembly process. In a multi-sensor redundant system, mutation point screening and weighted average processing can be performed to improve stability.

[0117] In step S500, the controller constructs a geometric fitting model according to the edge point coordinates. Preferably, when the number of edge points is not less than three, the least squares circle fitting method is used to calculate the center position and normal direction of the assembly hole. If the edge point is a three-dimensional space point, it is first projected to the current assembly surface, and then two-dimensional fitting is performed, and finally the three-dimensional hole center coordinates are reconstructed in combination with the normal vector. After obtaining the center point and normal line of the assembly hole, the controller compares the current center position and posture of the assembly end to obtain the position offset and posture angle error as the input basis for subsequent fine-tuning control. This process realizes the spatial accurate identification of complex assembly errors and is a key step in non-contact high-precision assembly control. Step S500 aims to calculate the center point and normal direction of the assembly hole based on the set of edge mutation points of the assembly hole identified in step S400, combined with the known size parameters of the assembly hole, the spatial installation calibration data between the infrared ranging sensor 610 and the assembly end, and further determine the spatial offset and posture angle error of the current assembly end axis relative to the assembly hole axis. These deviation information will serve as the basic input for the next step S600 fine-tuning compensation control.

[0118] Step S500: The controller determines the offset between the current assembly end axis of the assembly mechanism 40 and the assembly hole axis according to the edge position parameters and the size parameters of the assembly hole, combined with the known spatial coordinate relationship between the monitoring component 60 and the assembly end. The offset includes: At least three mutation points were detected.

[0119] The controller has completed the mutation point identification in step S400 and recorded the corresponding spatial coordinates. At least three valid edge points are obtained to form an edge point set: These point coordinates are usually mapped to the assembly coordinate system, taking into account the installation offset of the infrared ranging sensor.

[0120] Calculate the center coordinates of the assembly hole.

[0121] This step fits the circular geometry through the edge point set to determine the center point of the assembly hole and normal direction The Kasa least squares circle fitting algorithm is preferably used, and the calculation process is as follows: 2D circle fitting (simplified model, default assembly surface is plane). Assume the coordinates of the circle center are , edge point .

[0122] Fitting objective function: .

[0123] Linearize the equation and construct the following matrix: .

[0124] Solving linear equations ,in: , , .

[0125] 3D space circle center recovery (applicable to any posture surface).

[0126] First, all Project to the 2D plane where the current assembly face is located.

[0127] Use a 2D circle fitting algorithm to find the center .

[0128] Combined with the plane normal vector Restore the three-dimensional coordinates: .

[0129] in, is the local orthogonal basis of the surface, as a reference point.

[0130] Circular surface normal It can be obtained through PCA principal component analysis or edge point plane fitting.

[0131] Offset vector and attitude angle calculation.

[0132] The controller will fit the hole center coordinates The current center position of the assembly end of the assembly mechanism 40 Perform spatial difference calculation to obtain the position offset: .

[0133] In addition, if you need to determine whether the postures are consistent, compare the angles of the two direction vectors: the direction of the assembly end axis and the hole surface normal direction .

[0134] Attitude angle error calculation formula: .

[0135] Controller according to and Determine whether to proceed to the next step of fine-tuning compensation.

[0136] Specific: The purpose of posture consistency is to determine whether the current assembly end is aligned with the assembly hole on the side of the energy absorption box in the spatial direction (that is, not only the position is aligned, but also the direction is required to be consistent).

[0137] In high-precision assembly, the hole requires not only that the center position of the assembly end be aligned with the center of the hole, but also that the direction (axis direction) of the assembly end be consistent with the normal direction of the assembly hole. Otherwise, even if the position is aligned, assembly defects such as difficulty in insertion, jamming, and deflection may occur. This dual control of position and direction is called posture matching.

[0138] Moreover, the necessary and sufficient condition for the two directions to be consistent is that their direction vectors are collinear. The most direct way to determine whether two vectors are collinear is to calculate their angle .like If it is small enough (such as <0.5°), it can be regarded as "the same direction". This step uses the vector angle calculation formula to determine whether the current assembly posture meets the requirements.

[0139] Attitude error angle The detailed processing steps are as follows: First, get the two direction vectors.

[0140] Assembly end axis direction vector , the installation orientation of the assembly end is known in the system, or calculated in real time by the internal encoder / attitude sensor.

[0141] Usually the unit vector after the 3D posture solution is taken as the principal axis vector.

[0142] Mounting hole face normal vector The normal vector of the plane where the assembly hole is located is calculated when fitting the edge point circle in S520. The specific fitting method is: for example, the unit normal vector is extracted after constructing the fitting plane through PCA or the three-point rule.

[0143] Then, perform the standard vector angle calculation.

[0144] Use the following formula to calculate the angle between two vectors .

[0145] .

[0146] in: : is the dot product of two direction vectors.

[0147] : They are the modulus lengths of the two vectors (should be normalized).

[0148] arccos: Inverse cosine function, the output angle unit can be radians or degrees.

[0149] Next, a judgment threshold is set and a judgment result is output.

[0150] The controller sets an acceptable attitude error tolerance .

[0151] When Δθ≤0.5° is judged as acceptable, the assembly end direction is considered to be consistent with the hole normal.

[0152] When Δθ>0.5°, it is judged as unacceptable and requires attitude fine-tuning.

[0153] If the verticality requirement is not met, the system will issue a control instruction in S600 to allow the slewing mechanism 10 to perform a micro-angle compensation rotation around the axis.

[0154] For example: Assembly end axis direction: . Assembly hole normal direction: .

[0155] Calculating the dot product gives: .

[0156] Find the angle: .

[0157] Result: The boundary is reached, and if strict control is required, fine-tuning compensation is entered.

[0158] In step S600, the controller drives the displacement mechanism 50 and the rotary assembly 540 to coordinate compensation control according to the spatial offset and angle error between the current assembly end axis of the assembly mechanism 40 and the assembly hole axis. First, according to the position offset Δp, each moving assembly is controlled to make a slight correction along the X, Y, and Z directions to make the assembly end position close to the hole center; then, by calculating the attitude angle error Δθ between the assembly end axis and the assembly hole normal, the rotary assembly 540 is controlled to perform angle fine-tuning compensation, and gradually adjust the assembly end direction to be consistent with the assembly hole direction. The above process forms a closed-loop control. After the compensation is completed, if the deviation has met the set tolerance, the assembly preparation is marked as complete. If it exceeds the maximum number of compensation times and is still not met, the alarm process is triggered to ensure the accuracy of the hole operation and the stability of the system operation. The goal of this step is to drive the displacement component and the rotation component 540 of the assembly mechanism 40 to move in coordination based on the spatial offset and attitude angle error in position and direction between the assembly end and the assembly hole calculated in step S500, and to make fine adjustments and compensation for the position and direction of the assembly end so that the axis of the assembly end is completely collinear with the axis of the assembly hole in space with high precision.

[0159] Step S600 controls the second driving end 541 to drive the assembly mechanism 40 to perform fine adjustment compensation along the direction of the assembly end axis perpendicular to the side of the energy absorption box and / or around the direction parallel to the assembly end axis according to the offset, so that the assembly end axis coincides with the assembly hole axis, including: Step S600: Control the assembly mechanism 40 to perform fine adjustment compensation to achieve axis collinearity.

[0160] Step S610: Determine the deviation tolerance.

[0161] The controller receives the position offset vector Δp=(Δx, Δy, Δz) and the attitude angle error Δθ output in step S500, and compares them with the system set tolerance (such as Δp≤0.2mm, Δθ≤0.5°). If both items are within the tolerance range, the compensation is skipped and the assembly step is entered. Otherwise, the fine-tuning compensation process is entered.

[0162] Step S620: Perform position fine-tuning compensation. The controller drives the displacement mechanism to perform three-axis (X / Y / Z) micro-displacement according to each component of Δp. X-direction compensation is achieved by the first moving component, Y-direction compensation is achieved by the second moving component, and Z-direction compensation is achieved by the third moving component (or lifting mechanism). It is recommended to use a step size of 0.05 to 0.2 mm for each fine-tuning, and the maximum compensation range (such as ±2 mm) can be set.

[0163] Step S630: re-acquire the assembly end position and make a judgment.

[0164] After the displacement is completed, the system recalculates the current center position of the assembly end, compares it with the center of the assembly hole again, and updates Δp. If it is still out of tolerance, continue to perform position fine-tuning; if the position is aligned, enter the posture compensation judgment.

[0165] S640: Attitude compensation fine-tuning processing, including: Step S641: Posture error judgment.

[0166] Determine whether Δθ exceeds the attitude angle error tolerance.

[0167] If Δθ≤threshold (such as 0.5°), skip; otherwise enter attitude compensation control.

[0168] Step S642: Select the posture compensation axis.

[0169] The controller determines the direction of the error and chooses to rotate around the Z axis.

[0170] S640-3: Solve the rotation axis and angle.

[0171] Use the vector cross product to calculate the rotation axis vector: ; Rotation angle = Δθ × gain factor (or step angle compensation).

[0172] Step S644: driving the rotary mechanism 10 to adjust its posture.

[0173] Drive the servo rotary assembly 540 to rotate a specified angle. The recommended rotation angle for each rotation is 0.1° to 0.5°; After adjustment, the assembly end direction vector is re-obtained; A closed-loop control is formed until Δθ meets the requirement or exceeds the maximum compensation times, where the maximum compensation times should be set according to the actual situation.

[0174] S645: Verification and confirmation.

[0175] After the posture adjustment is completed, the angle Δθ is calculated. If it is within the tolerance range, it is judged as "posture alignment"; if it is still out of tolerance, exception processing is triggered.

[0176] Finally, if both Δp and Δθ meet the tolerance, the controller marks the axis collinearity completion status. The process enters the next assembly action (insertion, riveting, etc.). If alignment is still not possible after multiple rounds of compensation, the controller sends a fault signal, the system suspends the assembly action, prompts manual intervention or records an abnormality log.

[0177] The above contents described in this specification are merely examples of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, as long as they do not deviate from the contents of the present specification or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A rotary assembly tool for an energy absorption box, wherein: The side of the energy absorption box is provided with an assembly hole, and the size parameters of the assembly hole are known quantities, and the characteristics include: The slewing mechanism comprises a first driving end, wherein the first driving end is controlled to rotate around its own axis at a preset angle; A placement platform connected to the first driving end to move synchronously with the first driving end, the placement platform comprising a placement plane for placing the energy absorbing box, and a side surface of the energy absorbing box is perpendicular to the placement plane; A clamping mechanism is arranged on the placement plane, and the clamping mechanism is configured to limit the energy absorption box placed on the placement plane to a preset area when the rotary assembly tool is in a working state; The assembly mechanism comprises an assembly end, on which an assembly part is installed; The displacement mechanism comprises a second driving end for controlled movement, wherein the second driving end is connected to the assembly mechanism to drive the assembly mechanism to move synchronously; A monitoring component is arranged at a preset position on the assembly mechanism, so that the spatial position relationship between the monitoring component and the assembly end axis of the assembly mechanism is limited to a known quantity, and the monitoring component is configured to measure the edge position parameters of the assembly hole on the side of the energy absorption box when the rotary assembly tool is in a working state; A controller is electrically connected to the assembly mechanism, the displacement mechanism and the monitoring component, and the controller is configured to control the movement of the driving end of the displacement mechanism according to the measured edge position parameters of the assembly hole on the side of the energy absorption box and the size parameters of the assembly hole, so that the axis of the assembly end of the assembly mechanism connected to the second driving end is collinear with the axis of the assembly hole on the side of the energy absorption box.

2. A rotary assembly tool for an energy absorption box according to claim 1, characterized in that: The displacement mechanism comprises: A first moving component, comprising a first moving end that moves in a controlled manner, wherein a moving direction of the first moving end is parallel to the placement plane; a second mobile component connected to the first mobile end to move with the first mobile end, the second mobile component comprising a second mobile end that moves in a controlled manner, the moving direction of the second mobile end being parallel to the placement plane and parallel to the moving direction of the first mobile end; a third mobile component connected to the second mobile end to move with the second mobile end, the third mobile component comprising a third mobile end that moves in a controlled manner, and a moving direction of the third mobile end is perpendicular to the placement plane; A swivel assembly is connected to the third mobile end to move with the third mobile end, the swivel assembly includes a swivel end with controlled rotation, the rotation direction of the swivel end is parallel to the placement plane, and the swivel end is defined as the second driving end.

3. The rotary assembly tool for an energy absorption box according to claim 1, characterized in that: The monitoring component includes an infrared ranging sensor, which includes an emitting end for emitting an infrared light beam. The light beam emitted by the infrared ranging sensor is parallel to the axis of the assembly end of the assembly mechanism, and the emission direction of the infrared light beam of the emitting end is the same as the direction of the assembly end.

4. The rotary assembly tool for the energy absorption box according to claim 3, characterized in that: The number of the infrared distance measuring sensors is two, the two infrared distance measuring sensors are arranged in parallel, and the center points of the two infrared distance measuring sensors are both in a first plane, and the first plane is perpendicular to the axis of the transmitting end.

5. The rotary assembly tool for an energy absorption box according to claim 3, characterized in that: The number of the infrared ranging sensors is at least three, and each of the infrared ranging sensors is arranged at each endpoint of a regular polygon in a one-to-one correspondence, and the number of endpoints of the regular polygon is equal to the number of the infrared ranging sensors, and each of the infrared ranging sensors is arranged in parallel, and the center point of each of the infrared ranging sensors is in a second plane, and the second plane is perpendicular to the axis of the transmitting end.

6. The rotary assembly tool for an energy absorption box according to claim 1, characterized in that: The clamping mechanism comprises: A first positioning component, disposed on the placement plane, wherein the first positioning component comprises a controlled first limiting end; A second positioning component is arranged on the placement plane, and the second positioning component includes a controlled second limiting end; A third positioning assembly is arranged on the placement plane, and the third positioning assembly includes a controlled third limiting end; Wherein, when the clamping mechanism is in a working state, the first limiting end abuts against a side of the energy absorbing box placed on the placing plane away from the placing platform to limit the movement of the energy absorbing box along a first direction, the second limiting end abuts against a side of the energy absorbing box perpendicular to the placing plane to limit the movement of the energy absorbing box along a second direction, the second direction is perpendicular to the first direction, the third limiting end abuts against a side of the energy absorbing box perpendicular to the placing plane and perpendicular to the second direction to limit the movement of the energy absorbing box along a third direction, the third direction is arranged perpendicularly to the first direction and the second direction.

7. A control method for a rotating assembly tool for an energy absorption box according to claim 4 or 5, characterized in that: The midpoint of the preset area on the placement plane is defined as the coordinate origin; The control method comprises: Obtaining preset position parameters corresponding to the assembly holes on the side of the energy absorption box; Determine the motion trajectory of the second driving end of the displacement mechanism according to the coordinate origin, the preset position parameters corresponding to the assembly hole, and the preset angle of rotation of the first driving end, so that the axis of the assembly end of the assembly mechanism moves in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box; After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the infrared ranging sensor arranged on the assembly mechanism emits an infrared beam to obtain ranging data generated by the infrared beam irradiating the surface of the energy absorbing box; When the infrared light beam passes through the assembly hole and enters its inner cavity, the distance value measured by the infrared distance measuring sensor changes suddenly, and the edge position parameters of the assembly hole are determined according to the spatial position of the mutation point; The controller determines the offset between the current assembly end axis of the assembly mechanism and the assembly hole axis according to the edge position parameters and the size parameters of the assembly hole, combined with the known spatial coordinate relationship between the monitoring component and the assembly end; According to the offset, the second driving end is controlled to drive the assembly mechanism to perform fine-tuning compensation along the direction of the assembly end axis perpendicular to the side of the energy absorption box and / or around the direction parallel to the assembly end axis, so that the assembly end axis coincides with the assembly hole axis.

8. A control method according to claim 7, characterized in that: The step of determining the motion trajectory of the second driving end of the displacement mechanism according to the coordinate origin, the preset position parameters corresponding to the assembly hole and the preset angle of rotation of the first driving end, so that the axis of the assembly end of the assembly mechanism moves in a direction coaxial with the axis of the riveting hole on the side of the energy absorption box comprises: Obtaining a target spatial position of an assembly hole on a side of the energy absorption box in the rotary assembly tooling coordinate system; According to the preset angle of rotation of the first driving end, the preset assembly hole coordinates are transformed to obtain a real-time target position; The second driving end is controlled to move so as to move the axis of the assembly end to a preset vicinity of the axis of the target assembly hole.

9. A method according to claim 7, characterized in that: After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the step of emitting an infrared beam by the infrared ranging sensor arranged on the assembly mechanism to obtain ranging data generated by the infrared beam irradiating the surface of the energy absorbing box comprises: After the axis of the assembly end is moved to a preset vicinity of the axis of the assembly hole, the distance values ​​of the assembly end toward the surface of the energy absorbing box are respectively obtained by at least two infrared distance measuring sensors arranged on the assembly mechanism; If the differences between the distance values ​​measured by all the infrared distance measuring sensors are within the equipment error range, it is determined that the axis of the assembly end is perpendicular to the side of the energy absorption box on which the assembly hole is opened.

10. A method according to claim 7, characterized in that: When the infrared light beam passes through the assembly hole and enters the inner cavity thereof, the distance value measured by the infrared distance measuring sensor changes suddenly, and the step of determining the edge position parameter of the assembly hole according to the spatial position of the mutation point comprises: Determine whether a sudden change value appears in the infrared ranging sensor data, wherein the sudden change value is that the distance value acquired by the infrared ranging sensor changes instantaneously beyond an allowable range; If the mutation value is detected, the mutation point position is marked as the edge of the assembly hole.

Images