CN105547172A

CN105547172A - System and method for measuring repeatability precision of industrial robot on the basis of acupuncture luminescence method

Info

Publication number: CN105547172A
Application number: CN201610006388.5A
Authority: CN
Inventors: 刘东东; 谈士力; 陈浩; 李宝瑞
Original assignee: SHANGHAI UNIVERSITY
Current assignee: SHANGHAI UNIVERSITY
Priority date: 2016-01-06
Filing date: 2016-01-06
Publication date: 2016-05-04
Anticipated expiration: 2036-01-06
Also published as: CN105547172B

Abstract

The invention relates to a system and a method for measuring the repeatability of an industrial robot based on an acupuncture illumination method. The system includes a robot to be tested, a needle for detection, a soft cushion, an opaque black paper, a black box, a black paper with holes, a point light source, a black box support frame, a guide rail, a photocell array, a photocell support frame, a mobile platform, and a rail crank , Photocurrent detector and single-chip display system. In this method, the measurement accuracy of the measurement system is determined first, and then the repeatability accuracy of the robot to be detected is determined. The device of the invention has the advantages of simple structure, convenient implementation, low detection cost and high precision. According to the light amplification principle, the method of the invention measures the hole diameter and the hole spacing on the black paper with holes to finally obtain the repeatability of the end effector of the industrial robot.

Description

System and method for measuring repeatability accuracy of industrial robots based on acupuncture illumination method

技术领域technical field

本发明涉及一种基于针刺光照法测量工业机器人重复精度的系统和方法。The invention relates to a system and method for measuring the repeatability of an industrial robot based on an acupuncture illumination method.

背景技术Background technique

近年来由于老龄化程度加剧，适龄工作人口减少，导致了我国劳动力成本上升，人口红利急剧下降，工业产品的国际竞争力下降。工业机器人作为减少工作人员，提高工作效率，降低，劳动强度的有力武器，被越来越多的应用于工业生产的各个环节。In recent years, due to the intensification of aging and the reduction of the working-age population, the cost of labor in my country has risen, the demographic dividend has dropped sharply, and the international competitiveness of industrial products has declined. As a powerful weapon to reduce staff, improve work efficiency, and reduce labor intensity, industrial robots are increasingly used in all aspects of industrial production.

为了更好的适应多变的工作环境和工作对象，人们设计了种类繁多，结构各异的工业机器人，对机器人的各项性能也提出来更高的要求。机器人末端执行器重复精度是机器人综合性能指标中最重要的指标之一，它体现了机器人末端执行器多次从空间内任何一点到空间内固定点的精确定位能力。由于定位要求精度极高，某些工业机器人(如SCARA机器人)对重复精度要求达到0.01mm，所以对该指标的测量一直比较困难。市场上一般采用摄像机摄像的方法对末端执行器进行跟踪定位，然后提取录像中每一帧的图像，对其进行比较，计算出单位时间内目标移动的像素个数，从而得到末端执行器的位置信息；这种方法需要手工编程，其测量精度容易受到摄像机分辨率、拍摄位置、光照强度等因素的影响。In order to better adapt to the changing working environment and working objects, people have designed a wide variety of industrial robots with different structures, and put forward higher requirements for the performance of robots. The repeatability of the robot end effector is one of the most important indicators in the comprehensive performance index of the robot. It reflects the precise positioning ability of the robot end effector from any point in the space to a fixed point in the space many times. Due to the high precision required for positioning, some industrial robots (such as SCARA robots) require repeatability of 0.01mm, so the measurement of this indicator has always been difficult. In the market, the method of camera shooting is generally used to track and locate the end effector, and then extract the image of each frame in the video, compare them, and calculate the number of pixels that the target moves per unit time, so as to obtain the position of the end effector Information; this method requires manual programming, and its measurement accuracy is easily affected by factors such as camera resolution, shooting position, and light intensity.

发明内容Contents of the invention

针对现有技术存在的缺陷，本发明的目的是提供一种基于针刺光照法测量工业机器人重复精度的系统和方法。使其在测量精度、操作性和测量成本上都能够满足工业现场的需要。Aiming at the defects existing in the prior art, the object of the present invention is to provide a system and method for measuring the repeatability of industrial robots based on the acupuncture illumination method. It can meet the needs of industrial sites in terms of measurement accuracy, operability and measurement cost.

为达到上述目的，本发明采用如下技术方案：To achieve the above object, the present invention adopts the following technical solutions:

一种基于针刺光照法测量工业机器人重复精度的系统，包括待检测机器人，检测用针，软性垫物，不透光黑纸，黑箱，带孔黑纸，点光源，黑箱支撑架，导轨，光电池阵列，光电池支撑架，移动平台，导轨摇把，光电流检测仪和单片机显示系统；所述检测用针安装在待检测机器人的末端执行器上，所述不透光黑纸平整地固定在软性垫物上，检测用针的安装方向与不透光黑纸保持垂直，移动末端执行器，使得检测用针作用在不透光黑纸上后形成带孔黑纸；所述黑箱固定在黑箱支撑架上，点光源安装在黑箱的中心处，所述黑箱的前侧面开口，开口端的两侧设有插槽，所述带孔黑纸插于插槽内固定；所述黑箱支撑架安装在导轨的一端，所述移动平台安装在导轨上，通过导轨摇把带动沿导轨水平移动；所述光电池阵列通过光电池支撑架安装在移动平台上，光电池阵列的中心与点光源的高度相同；所述光电流检测仪和单片机显示系统连接在一起，安装在光电池阵列的背面。A system for measuring the repeatability of industrial robots based on acupuncture lighting method, including a robot to be tested, a needle for testing, a soft pad, opaque black paper, a black box, black paper with holes, a point light source, a black box support frame, and a guide rail , a photocell array, a photocell support frame, a mobile platform, a guide rail crank, a photocurrent detector and a single-chip display system; the detection needle is installed on the end effector of the robot to be detected, and the opaque black paper is flatly fixed On the soft mat, the installation direction of the detection needle is kept perpendicular to the opaque black paper, and the end effector is moved so that the detection needle acts on the opaque black paper to form black paper with holes; the black box is fixed On the black box support frame, the point light source is installed at the center of the black box, the front side of the black box is open, and the two sides of the opening end are provided with slots, and the black paper with holes is inserted into the slot and fixed; the black box support frame Installed on one end of the guide rail, the mobile platform is installed on the guide rail, and is driven to move horizontally along the guide rail by the guide rail crank; the photocell array is installed on the mobile platform through the photocell support frame, and the center of the photocell array is the same as the height of the point light source; The photoelectric current detector and the single-chip microcomputer display system are connected together and installed on the back of the photocell array.

一种基于针刺光照法测量工业机器人重复精度的方法，包括如下步骤：A method for measuring the repeatability of an industrial robot based on an acupuncture illumination method, comprising the steps of:

步骤1，将检测用针固定在待检测机器人的末端执行器上，安装方向与不透光黑纸垂直，移动末端执行器，使检测用针能够刺透不透光黑纸，重复执行n次步骤1，执行时保证每一个针刺的小孔不重叠，形成带孔黑纸；Step 1, fix the detection needle on the end effector of the robot to be tested, the installation direction is perpendicular to the opaque black paper, move the end effector so that the detection needle can pierce the opaque black paper, repeat n times Step 1. When executing, ensure that each needled hole does not overlap to form black paper with holes;

步骤2，确定测量系统的测量精度：将步骤1的带孔黑纸插入到黑箱的插槽内固定，关闭室内灯光，打开点光源，转动导轨摇把带动移动平台沿导轨移动，使得点光源通过带孔黑纸射出的所有光线都能投射到光电池阵列上形成光斑，光电流检测仪接收到光信号后转化为电信号传递给单片机显示系统，读取单片机显示系统的读数i₂；撤出带孔黑纸，使点光源射出的光线直接投射到光电池阵列上，再读取单片机显示系统的读数i；则此时满足关系式Step 2, determine the measurement accuracy of the measurement system: Insert the black paper with holes in step 1 into the slot of the black box and fix it, turn off the indoor light, turn on the point light source, turn the handle of the guide rail to drive the mobile platform to move along the guide rail, so that the point light source passes through All the light emitted from the black paper with holes can be projected onto the photocell array to form a light spot. After receiving the light signal, the photocurrent detector converts it into an electrical signal and transmits it to the single-chip microcomputer display system to read the reading i ₂ of the single-chip microcomputer display system; withdraw the belt Hole black paper, so that the light emitted by the point light source is directly projected onto the photocell array, and then read the reading i of the single-chip display system; then the relational expression is satisfied at this time

$\frac{{i i}_{22}}{i i} = = \frac{{S S}_{22}}{S S} - - - - - - ((11))$

其中S₂表示有带孔黑纸时，点光源通过带孔黑纸射出的所有光线投射到光电池阵列上形成所有光斑的面积之和，S表示撤出带孔黑纸，点光源射出的光线直接投射到光电池阵列上的面积；Among them, S ₂ represents the sum of the areas of all light spots formed by the light emitted by the point light source through the black paper with holes projected on the photocell array when there is black paper with holes, and S represents the withdrawal of the black paper with holes, and the light emitted by the point light source is directly the area projected onto the photovoltaic array;

则求得光电池阵列上一个光斑的面积为：Then the area of a light spot on the photocell array is obtained as:

S₃＝S₂/n(2)S ₃ =S ₂ /n(2)

以及光电池阵列上一个光斑的直径为：And the diameter of a light spot on the photocell array is:

${d d}_{22} = = \sqrt{\frac{44 {S S}_{33}}{π π}} - - - - - - ((33))$

在导轨上读取此时点光源到光电池阵列的距离l₂，点光源到带孔黑纸的距离l₁由黑箱的大小决定；通过光照原理可得Read the distance l ₂ from the point light source to the photocell array on the guide rail at this time, and the distance l ₁ from the point light source to the black paper with holes is determined by the size of the black box;

$\frac{{l l}_{22}}{{l l}_{11}} = = \frac{{d d}_{22}}{{d d}_{11}} - - - - - - ((44))$

其中d₂为光电池阵列上一个光斑的直径，d₁为带孔黑纸上一个小孔的直径；Where d ₂ is the diameter of a light spot on the photocell array, and d ₁ is the diameter of a small hole on the black paper with holes;

求得一个小孔直径d₁：Find a hole diameter d ₁ :

${d d}_{11} = = \frac{{l l}_{11}}{{l l}_{22}} \cdot \cdot \sqrt{\frac{44}{n no π π} \cdot \cdot \frac{{i i}_{22}}{i i} \cdot \cdot S S} - - - - - - ((55))$

该孔径d₁表明了测量系统的测量精度； _The aperture d1 indicates the measurement accuracy of the measurement system;

步骤3：重新换一张不透光黑纸，移动待检测机器人末端执行器从空间任何一点到被测点，将检测用针刺透不透光黑纸，重复执行n次步骤3，此时不透光黑纸上的小孔一定会有重叠的，形成带孔黑纸；Step 3: Change another piece of opaque black paper, move the end effector of the robot to be tested from any point in space to the point to be tested, prick the opaque black paper with the detection needle, and repeat step 3 n times, at this time The small holes on the opaque black paper must overlap to form black paper with holes;

步骤4：确定待检测机器人的重复精度σ：将步骤3的带孔黑纸插入到黑箱的插槽内固定，关闭室内灯光，打开点光源，转动导轨摇把带动移动平台沿导轨移动，使得点光源通过带孔黑纸射出的所有光线都能投射到光电池阵列上形成光斑，光电流检测仪接收到光信号后转化为电信号传递给单片机显示系统，读取单片机显示系统的读数i′₂；撤出带孔黑纸，使点光源射出的光线直接投射到光电池阵列上，再读取单片机显示系统的读数i；则此时满足关系式Step 4: Determine the repeatability of the robot to be tested σ: Insert the perforated black paper in step 3 into the slot of the black box and fix it, turn off the indoor light, turn on the point light source, turn the handle of the guide rail to drive the mobile platform to move along the guide rail, so that the point All the light emitted by the light source through the black paper with holes can be projected onto the photocell array to form light spots. After receiving the light signal, the photocurrent detector converts it into an electrical signal and transmits it to the single-chip display system to read the reading i′ ₂ of the single-chip display system; Withdraw the black paper with holes so that the light emitted by the point light source is directly projected onto the photocell array, and then read the reading i of the single-chip microcomputer display system; then the relational expression is satisfied at this time

$\frac{{i i}_{22}^{' '}}{i i} = = \frac{{S S}_{22}^{' '}}{S S} - - - - - - ((66))$

其中S′₂表示有带孔黑纸时，点光源通过带孔黑纸射出的所有光线投射到光电池阵列上形成所有光斑的面积之和；Wherein S' ₂ represents when there is black paper with holes, the sum of the areas of all light spots formed on the photocell array by the point light source projecting on the photocell array through all the light rays emitted by the black paper with holes;

由于有些小孔是重叠甚至重合的，所以S′₂＜S₂；最后计算出重复精度σ值越小表明重复精度越高；理想情况下，如果所有孔都是重合的，则理想重复精度 Since some small holes overlap or even overlap, S′ ₂ <S ₂ ; finally calculate the repeatability Smaller σ values indicate higher repeatability; ideally, if all holes are coincident, ideal repeatability

与现有技术相比，本发明具有如下突出的实质性特点和显著的优点：Compared with the prior art, the present invention has the following prominent substantive features and remarkable advantages:

本发明装置结构简单，实施方便，检测成本低，精度高。本发明方法根据光照放大原理，通过测量带孔黑纸上的孔径以及孔间距，最终得到该工业机器人末端执行器的重复精度。The device of the invention has the advantages of simple structure, convenient implementation, low detection cost and high precision. According to the light amplification principle, the method of the invention measures the hole diameter and the hole spacing on the black paper with holes to finally obtain the repeatability of the end effector of the industrial robot.

附图说明Description of drawings

图1为工业机器人带针示意图。Figure 1 is a schematic diagram of an industrial robot with a needle.

图2为光照检测装置示意图。Figure 2 is a schematic diagram of an illumination detection device.

图3为光电流检测仪和单片机显示系统示意图。Figure 3 is a schematic diagram of a photocurrent detector and a single-chip microcomputer display system.

图4为光照原理示意图。Figure 4 is a schematic diagram of the lighting principle.

具体实施方式detailed description

下面结合附图，对本发明的具体实施例做进一步的说明。The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

如图1至图3所示，一种基于针刺光照法测量工业机器人重复精度的系统，包括待检测机器人1，检测用针2，软性垫物3，不透光黑纸4，黑箱5，带孔黑纸6，点光源7，黑箱支撑架8，导轨9，光电池阵列10，光电池支撑架11，移动平台12，导轨摇把13，光电流检测仪14和单片机显示系统15；所述检测用针2安装在待检测机器人1的末端执行器上，所述不透光黑纸4平整地固定在软性垫物3上，检测用针2的安装方向与不透光黑纸4保持垂直，移动末端执行器，使得检测用针2作用在不透光黑纸4上后形成带孔黑纸6；所述黑箱5固定在黑箱支撑架8上，点光源7安装在黑箱5的中心处，所述黑箱5的前侧面开口，开口端的两侧设有插槽，所述带孔黑纸6插于插槽内固定；所述黑箱支撑架8安装在导轨9的一端，所述移动平台12安装在导轨9上，通过导轨摇把13带动沿导轨9水平移动；所述光电池阵列10通过光电池支撑架11安装在移动平台12上，光电池阵列10的中心与点光源7的高度相同；所述光电流检测仪14和单片机显示系统15连接在一起，安装在光电池阵列10的背面。As shown in Figures 1 to 3, a system for measuring the repeatability of industrial robots based on the acupuncture illumination method includes a robot to be tested 1, a detection needle 2, a soft pad 3, opaque black paper 4, and a black box 5 , black paper with holes 6, point light source 7, black box support frame 8, guide rail 9, photocell array 10, photocell support frame 11, mobile platform 12, guide rail crank handle 13, photocurrent detector 14 and single-chip microcomputer display system 15; The detection needle 2 is installed on the end effector of the robot 1 to be detected, the opaque black paper 4 is flatly fixed on the soft cushion 3, and the installation direction of the detection needle 2 is kept in line with the opaque black paper 4 Vertically, move the end effector so that the detection needle 2 acts on the opaque black paper 4 to form a black paper 6 with holes; the black box 5 is fixed on the black box support frame 8, and the point light source 7 is installed in the center of the black box 5 , the front side of the black box 5 is open, and slots are provided on both sides of the opening, and the black paper 6 with holes is inserted into the slot and fixed; the black box support frame 8 is installed on one end of the guide rail 9, and the moving The platform 12 is installed on the guide rail 9, and is driven by the guide rail crank 13 to move horizontally along the guide rail 9; the photocell array 10 is installed on the mobile platform 12 through the photocell support frame 11, and the center of the photocell array 10 is the same as the height of the point light source 7; The photocurrent detector 14 is connected with the single-chip microcomputer display system 15 and installed on the back of the photocell array 10 .

如图4所示，所谓光照法实际上是利用小孔成像原理将被测小孔放大到方便测量的程度，点光源在A点发出光线，透过B点处的两个小孔，到达位于C点的屏幕上，则被测小孔间距a与屏幕上两光斑间距b满足关系线段AB和AC的长度可直接读出，光斑间距b可由测量得出，最终可计算得出被测小孔间距a。As shown in Figure 4, the so-called illumination method actually uses the principle of small hole imaging to enlarge the measured small hole to a convenient measurement level. The point light source emits light at point A, passes through two small holes at point B, and reaches the On the screen at point C, the distance a between the measured pinholes and the distance b between the two light spots on the screen satisfy the relationship The lengths of the line segments AB and AC can be read directly, the spot distance b can be obtained by measurement, and finally the measured hole distance a can be calculated.

基于上述原理，一种基于针刺光照法测量工业机器人重复精度的方法，包括如下步骤：Based on the above principles, a method for measuring the repeatability of industrial robots based on the acupuncture illumination method includes the following steps:

步骤1，将检测用针2(直径约0.1mm)固定在待检测机器人1的末端执行器上，安装方向与不透光黑纸4垂直，移动末端执行器，使检测用针2能够刺透不透光黑纸4，重复执行50次步骤1，执行时保证每一个针刺的小孔不重叠，形成带孔黑纸6；Step 1, fix the detection needle 2 (about 0.1 mm in diameter) on the end effector of the robot 1 to be detected, the installation direction is perpendicular to the opaque black paper 4, and move the end effector so that the detection needle 2 can penetrate Opaque black paper 4, repeat step 1 50 times, and ensure that each acupuncture hole does not overlap to form black paper 6 with holes;

步骤2，确定测量系统的测量精度：将步骤1的带孔黑纸6插入到黑箱5的插槽内固定；关闭室内灯光，打开点光源7(波长λ＝780nm)，此时点光源7与带孔黑纸6的间距为1cm；转动导轨摇把13带动移动平台12沿导轨9移动，使得点光源7通过带孔黑纸6射出的所有光线都能投射到光电池阵列10上形成光斑，这里采用HAMAMATSU公司出品的500片硅感光片(每片感光面积1.175x2，每片间距0.4，单位mm，并联连接)组成的光电池阵列(面积400x480，单位mm)；通过导轨9读数可知，点光源7与光电池阵列10的间距为30cm；光电流检测仪14接收到光信号后转化为电信号传递给单片机显示系统15，读取单片机显示系统15的读数i₂＝10mA；撤出带孔黑纸6，使点光源7射出的光线直接投射到光电池阵列10上，再读取单片机显示系统15的读数i＝30mA；则此时满足关系式Step 2, determine the measurement accuracy of the measurement system: insert the black paper 6 with holes in step 1 into the slot of the black box 5 and fix it; turn off the indoor light, turn on the point light source 7 (wavelength λ=780nm), and now the point light source 7 and The pitch of the black paper 6 with holes is 1 cm; the rotating handle 13 of the guide rail drives the mobile platform 12 to move along the guide rail 9, so that all the light emitted by the point light source 7 through the black paper 6 with holes can be projected onto the photocell array 10 to form a light spot, here A photocell array (area 400x480, unit mm) composed of 500 silicon photosensitive sheets (each photosensitive area 1.175x2, each sheet spacing 0.4, unit mm, connected in parallel) produced by HAMAMATSU Company; it can be known from the readings of the guide rail 9 that the point light source 7 and The spacing of the photocell array 10 is 30cm; Photocurrent detector 14 receives the light signal and converts it into an electrical signal and transmits it to the single-chip microcomputer display system 15, and reads the reading i ₂ =10mA of the single-chip microcomputer display system 15; withdraws the black paper 6 with holes, Make the light emitted by the point light source 7 directly project on the photocell array 10, and then read the reading i=30mA of the single-chip microcomputer display system 15; then satisfy the relational expression at this moment

$\frac{{i i}_{22}}{i i} = = \frac{{S S}_{22}}{S S} = = 0.33 0.33 - - - - - - ((11))$

其中S₂表示有带孔黑纸6时，点光源7通过带孔黑纸6射出的所有光线投射到光电池阵列10上形成所有光斑的面积之和，S表示撤出带孔黑纸6，点光源7射出的光线直接投射到光电池阵列10上的面积，S＝1.92×10⁵mm²；这样可得S₂＝0.33S＝6.4×10⁴mm²。Wherein S ₂ represents when there is the black paper with holes 6, the point light source 7 projects the sum of the areas of all light spots formed on the photocell array 10 through the black paper with holes 6, and S represents that the black paper with holes 6 is withdrawn. The area where the light from the light source 7 is directly projected onto the photocell array 10 is S=1.92×10 ⁵ mm ² ; thus, S ₂ =0.33S=6.4×10 ⁴ mm ² .

则求得光电池阵列10上一个光斑的面积为：Then obtain the area of a light spot on the photocell array 10 as:

S₃＝S₂/n＝6.4×10⁴/50＝1280mm²(2)S ₃ =S ₂ /n=6.4×10 ⁴ /50=1280mm ² (2)

以及光电池阵列10上一个光斑的直径为：And the diameter of a light spot on the photocell array 10 is:

${d d}_{22} = = \sqrt{\frac{44 {S S}_{33}}{π π}} = = 40.4 40.4 m m m m - - - - - - ((33))$

在导轨9上读取此时点光源7到光电池阵列10的距离l₂＝30cm，点光源7到带孔黑纸6的距离由黑箱5的大小决定，l₁＝1cm；通过光照原理可得Read on the guide rail 9 the distance l ₂ =30cm from the point light source 7 to the photocell array 10 at this time, the distance from the point light source 7 to the black paper 6 with holes is determined by the size of the black box 5, l ₁ =1cm; it can be obtained by the principle of illumination

$\frac{{l l}_{22}}{{l l}_{11}} = = \frac{{d d}_{22}}{{d d}_{11}} = = 0.033 0.033 - - - - - - ((44))$

其中d₂为光电池阵列10上一个光斑的直径，d₁为带孔黑纸6上一个小孔的直径；Wherein d ₂ is the diameter of a light spot on the photocell array 10, and d ₁ is the diameter of an aperture on the black paper 6 with holes;

求得一个小孔直径d₁：Find a hole diameter d ₁ :

${d d}_{11} = = \frac{{l l}_{11}}{{l l}_{22}} \cdot \cdot \sqrt{\frac{44}{n no π π} \cdot \cdot \frac{{i i}_{22}}{i i} \cdot \cdot S S} = = 0.13 0.13 m m m m - - - - - - ((55))$

步骤3：重新换一张不透光黑纸4，移动待检测机器人1末端执行器从空间任何一点到被测点，将检测用针2刺透不透光黑纸4，重复执行50次步骤3，此时不透光黑纸4上的小孔一定会有重叠的，形成带孔黑纸6；Step 3: Change another piece of opaque black paper 4, move the end effector of the robot 1 to be tested from any point in space to the point to be tested, pierce the detection needle 2 through the opaque black paper 4, and repeat the steps 50 times 3. At this time, the small holes on the opaque black paper 4 must overlap to form a black paper 6 with holes;

步骤4：确定待检测机器人1的重复精度σ：将步骤3的带孔黑纸6插入到黑箱5的插槽内固定，关闭室内灯光，打开点光源7，转动导轨摇把13带动移动平台12沿导轨9移动，使得点光源7通过带孔黑纸6射出的所有光线都能投射到光电池阵列10上形成光斑，光电流检测仪14接收到光信号后转化为电信号传递给单片机显示系统15，读取单片机显示系统15的读数i′₂＝6mA；撤出带孔黑纸6，使点光源7射出的光线直接投射到光电池阵列10上，再读取单片机显示系统15的读数i＝30mA；则此时满足关系式Step 4: Determine the repeatability σ of the robot 1 to be tested: insert the perforated black paper 6 in step 3 into the slot of the black box 5 and fix it, turn off the indoor light, turn on the point light source 7, and turn the guide rail handle 13 to drive the mobile platform 12 Move along the guide rail 9, so that all the light emitted by the point light source 7 through the black paper 6 with holes can be projected onto the photocell array 10 to form a light spot, and the photocurrent detector 14 converts the light signal after receiving it into an electrical signal and transmits it to the single-chip display system 15 , read the reading i′ ₂ =6mA of the single-chip display system 15; withdraw the black paper 6 with holes, make the light emitted by the point light source 7 directly project on the photocell array 10, and then read the reading i=30mA of the single-chip display system 15 ; then the relation

其中S′₂表示有带孔黑纸6时，点光源7通过带孔黑纸6射出的所有光线投射到光电池阵列10上形成所有光斑的面积之和，可知此时S′₂＝3.84×10⁴mm²；Wherein S' ₂ represents when there is black paper with holes 6, the point light source 7 projects the sum of the areas of all light spots formed on the photocell array 10 through all the light rays emitted by the black paper with holes 6, it can be seen that S' ₂ =3.84×10 at this time ⁴ mm ² ;

由于有些小孔是重叠甚至重合的，所以S′₂＜S₂；最后计算出重复精度σ值越小表明重复精度越高；理想情况下，如果所有孔都是重合的，则理想重复精度 $σ^{'} = \frac{{S_{2}}^{'}}{{nS}_{2}} = 0.012.$ Since some small holes overlap or even overlap, S′ ₂ <S ₂ ; finally calculate the repeatability Smaller σ values indicate higher repeatability; ideally, if all holes are coincident, ideal repeatability $σ^{'} = \frac{{S_{2}}^{'}}{{wxya}_{2}} = 0.012.$

Claims

1. A system based on the acupuncture illumination method to measure the repeatability of an industrial robot, is characterized in that it comprises a robot to be detected (1), a needle (2) for detection, a soft mat (3), and an opaque black paper ( 4), black box (5), black paper with holes (6), point light source (7), black box support frame (8), guide rail (9), photocell array (10), photocell support frame (11), mobile platform ( 12), guide rail crank (13), photoelectric current detector (14) and single-chip microcomputer display system (15); Described detection needle (2) is installed on the end effector of robot (1) to be detected, and described not The light-transmitting black paper (4) is flatly fixed on the soft pad (3), the installation direction of the detection needle (2) is kept perpendicular to the opaque black paper (4), and the end effector is moved so that the detection needle (2) act on the opaque black paper (4) to form black paper with holes (6); the black box (5) is fixed on the black box support frame (8), and the point light source (7) is installed on the black box (5) ), the front side of the black box (5) is open, and slots are provided on both sides of the opening, and the black paper with holes (6) is inserted into the slot for fixing; the black box support frame (8) is installed At one end of the guide rail (9), the mobile platform (12) is installed on the guide rail (9), driven by the guide rail crank (13) to move horizontally along the guide rail (9); the photocell array (10) passes through the photocell support frame (11) be installed on the mobile platform (12), the height of the center of photocell array (10) is identical with point light source (7); Described photocurrent detector (14) is connected together with single-chip microcomputer display system (15), install On the back side of the photovoltaic cell array (10).

2. A method for measuring the repeatability of an industrial robot based on an acupuncture illumination method, characterized in that it comprises the steps:

Step 1, fix the detection needle (2) on the end effector of the robot to be detected (1), the installation direction is perpendicular to the opaque black paper (4), and move the end effector so that the detection needle (2) can Pierce through the opaque black paper (4), repeat step 1 n times, and ensure that the small holes of each needle punch do not overlap to form black paper with holes (6);

Step 2, determine the measurement accuracy of the measurement system: Insert the perforated black paper (6) in step 1 into the slot of the black box (5) and fix it, turn off the indoor light, turn on the point light source (7), and turn the handle of the guide rail (13 ) drives the mobile platform (12) to move along the guide rail (9), so that all the light emitted by the point light source (7) through the black paper with holes (6) can be projected onto the photocell array (10) to form a light spot, and the photocurrent detector ( 14) After receiving the optical signal, convert it into an electrical signal and deliver it to the single-chip display system (15), read the reading _i2 of the single-chip display system (15); withdraw the black paper with holes (6), and make the point light source (7) shoot out The light is directly projected onto the photocell array (10), and then the reading i of the single-chip display system (15) is read; then the relational expression is satisfied at this moment

\frac{{i i}_{22}}{i i} = = \frac{{S S}_{22}}{S S} - - - - - - ((11))

Wherein S ₂ represents when there is black paper with holes (6), the point light source (7) projects the sum of the areas of all light spots formed on the photocell array (10) through all the rays emitted by the black paper with holes (6), and S represents withdrawal Out of the black paper with holes (6), the light emitted by the point light source (7) is directly projected onto the area of the photocell array (10);

Then obtain the area of a light spot on the photocell array (10) as:

S ₃ =S ₂ /n(2)

And the diameter of a light spot on the photocell array (10) is:

{d d}_{22} = = \sqrt{\frac{44 {S S}_{33}}{π π}} - - - - - - ((33))

Read the distance l 2 from the point light source (7) to the photocell array (10) at this time on the guide rail (9), and the distance _l ₁ from the point light source (7) to the black paper with holes (6) is determined by the size of the black box (5) determined; available through the principle of illumination

\frac{{l l}_{22}}{{l l}_{11}} = = \frac{{d d}_{22}}{{d d}_{11}} - - - - - - ((44))

Wherein d ₂ is the diameter of a light spot on the photocell array (10), and d ₁ is the diameter of an aperture on the black paper with holes (6);

Find a hole diameter d ₁ :

{d d}_{11} = = \frac{{l l}_{11}}{{l l}_{22}} \cdot \cdot \sqrt{\frac{44}{n no π π} \cdot \cdot \frac{{i i}_{22}}{i i} \cdot \cdot S S} - - - - - - ((55))

_The aperture d1 indicates the measurement accuracy of the measurement system;

Step 3: Change another piece of opaque black paper (4), move the end effector of the robot to be tested (1) from any point in space to the point to be tested, and pierce the detection needle (2) through the opaque black paper ( 4), repeat step 3 n times, at this time, the small holes on the opaque black paper (4) must overlap to form black paper with holes (6);

Step 4: Determine the repeatability σ of the robot (1) to be tested: Insert the perforated black paper (6) in step 3 into the slot of the black box (5) and fix it, turn off the indoor light, turn on the point light source (7), and rotate The guide rail crank (13) drives the mobile platform (12) to move along the guide rail (9), so that all the light emitted by the point light source (7) through the black paper with holes (6) can be projected onto the photocell array (10) to form light spots, Photocurrent detector (14) is converted into electric signal after receiving light signal and passes to single-chip microcomputer display system (15), reads the reading i ' of single-chip microcomputer display system ( ₁₅ ); Withdrawal band hole black paper (6), makes The light emitted by the point light source (7) is directly projected onto the photocell array (10), and then the reading i of the single-chip microcomputer display system (15) is read; then the relational expression is satisfied at this time

\frac{{i i}_{22}^{' '}}{i i} = = \frac{{S S}_{22}^{' '}}{S S} - - - - - - ((66))

Wherein S' ₂ represents when there is the black paper with holes (6), the point light source (7) is projected onto the photocell array (10) to form the sum of the areas of all light spots by all the rays emitted by the black paper with holes (6);

Since some small holes overlap or even overlap, S′ ₂ <S ₂ ; finally calculate the repeatability Smaller σ values indicate higher repeatability; ideally, if all holes are coincident, ideal repeatability