CN106994687A - Industrial robot end six-dimension force sensor Installation posture scaling method - Google Patents

Abstract

The invention discloses a kind of industrial robot end six-dimension force sensor Installation posture scaling method, moved by control machine people along the reference axis of its own, due to the inertia force in motion, each axle reading of six-dimension force sensor is caused to change, so as to calibrate the direction relationses of robot corresponding axis and sensor coordinates axle by corresponding sensor reading, realize that the relative attitude of sensor coordinate system and robot coordinate system are demarcated.The Installation posture scaling method of the present invention can determine the transformational relation between sensor coordinate system and robot coordinate system, and then sensing data be changed to robot coordinate system, the motion control for robot.

Description

Industrial robot end six-dimension force sensor Installation posture scaling method

Technical field

The invention belongs to industrial robot technical field of sensory control, and in particular to a kind of industrial robot end six-dimensional force Sensor Installation posture scaling method.

Background technology

Six-dimension force sensor is often arranged on robot end, for the end stress letter in the robot measurement course of work Breath.Six-dimension force sensor has its own intrinsic coordinate system, three-dimensional orthogonal power and three that can be in any power system of measurement space Orthogonal dimension torque.Coordinate system of the data that six-dimension force sensor is directly measured based on its own.In addition, industrial robot also has Its own intrinsic coordinate system, six-dimension force sensor is arranged on after robot end, it is desirable to anti-by the data of force snesor Control machine people motion is presented, so, it is necessary first to clear and definite sensor and the installation relation in the machine human world, so that it is determined that going out sensor Transformational relation between coordinate system and robot coordinate system, and then sensing data can be changed to robot coordinate system, use In the motion control of robot.

At present, the installation relation in sensor and the machine human world relies primarily on machinery positioning determination, by design robot with On the adaptor of sensor, and the Design Orientation feature on adaptor, such as pin, pin-and-hole, with robot end, sensor Pin, pin-and-hole coordinate, it is ensured that sensor and the installation relation in the machine human world.By the design size of adaptor, biography is directly obtained Posture transformational relation between sensor and robot coordinate system.The posture transformational relation that this method is obtained depends on robot end Interface, adaptor, the machining accuracy of sensor mounting interface three, machining error can bring corresponding posture to change Error.

To solve Dependence Problem of the posture conversion accuracy to each part machining accuracy, the present invention proposes industrial robot End six-dimension force sensor Installation posture online calibration method, after sensor and robot are installed with any attitude and fixed, The installation relation of sensor and the machine human world can be calibrated, obtained certainly posture transformational relation and part machining accuracy without Close, this helps to break through limitation of the part machining accuracy to posture conversion accuracy, further improves robot and feels accordingly Answer control accuracy.

The content of the invention

Based on this, it is an object of the invention to provide a kind of demarcation of industrial robot end six-dimension force sensor Installation posture Method, solve six-dimension force sensor robot end's Installation posture problem of calibrating, by control machine people along its own Reference axis is moved, and due to the inertia force in motion, causes each axle reading of six-dimension force sensor to change, so as to by right The sensor reading answered calibrates the direction relationses of robot corresponding axis and sensor coordinates axle, realizes sensor coordinate system Demarcated with the relative attitude of robot coordinate system.

The present invention is achieved through the following technical solutions：

Industrial robot end six-dimension force sensor Installation posture scaling method, comprises the following steps：

1) workpiece with certain mass is fixedly installed in six-dimension force sensor tool ends end, in the static shape of industrial robot Under state, the force data of three axles of six-dimension force sensor is read, as initial value, wherein：

2) control industrial robot does positive accelerated motion along tool coordinates system X-axis, during which gathers six-dimension force sensor number According toCalculating obtain unit of the robot tool coordinate system X-axis under six-dimension force sensor coordinate system to Amount：

3) control industrial robot does positive accelerated motion along tool coordinates system Y-axis, during which gathers six-dimension force sensor number According toCalculating obtain unit of the robot tool coordinate system Y-axis under six-dimension force sensor coordinate system to Measure and be：

4) control industrial robot does positive accelerated motion along tool coordinates system Z axis, during which gathers six-dimension force sensor number According toCalculating obtain unit of the robot tool coordinate system Z axis under six-dimension force sensor coordinate system to Measure and be：

5) by step 2), result of calculation 3), 4), obtain being tied to six-dimension force sensor coordinate system by robot tool coordinate Posture changing matrix：

It is that robot tool coordinate can be achieved to be tied to posture between six-dimension force sensor coordinate system using the posture changing matrix Mutual conversion, demarcation so far complete.

In above-mentioned technical proposal, the robot is the 6DOF industrial robot of tandem.

Above-mentioned technical proposal step 2) in, control machine people does positive accelerated motion along tool coordinates system X-axis, it is assumed that period The acceleration at a certain moment is expressed as under robot tool coordinate system：

ThenIt is expressed as under six-dimension force sensor coordinate system：

Assuming that the load quality at six-dimension force sensor sensitivity end is m, then robot accelerates the load inertia power brought For：

During robot motion, the power that six-dimension force sensor is measured is by starting forceAnd inertia forceComposition, i.e.,：

Then obtain：

Due toBe unit vector, then formula (2) can obtain by formula (10), according to same principle can derive formula (3), (4)。

Six-dimension force sensor Installation posture scaling method in industrial robot end proposed by the present invention can determine sensing Transformational relation between device coordinate system and robot coordinate system, and then sensing data can be changed to robot coordinate system, Motion control for robot.

Brief description of the drawings

Fig. 1 is arranged on the view on industrial robot for the six-dimension force sensor of the present invention.

Wherein, 1- robots；2- six-dimension force sensors；3- workpiece；4- fixtures；5- robot end's flanges.

Embodiment

Introduced below is the embodiment as content of the present invention, below by embodiment to this The content of invention is made further to illustrate.Certainly, the not Tongfang of description following detailed description only for the example present invention The content in face, and should not be construed as limiting the scope of the invention.

As shown in figure 1, the fixing end of six-dimension force sensor 2 is connected to robot end's flange 5, six-dimension force sensor 2 is sensitive Jockey 4 on end, the clamping workpiece 3 of fixture 4.

The tool coordinates system of robot 1 is connected with end flange 5, and the coordinate system of six-dimension force sensor 2 is connected with its own.

Define coordinate system as follows：

The tool coordinates system OT-XTYTZT of robot 1；

The coordinate system OS-XSYSZS of six-dimension force sensor 2.

Under static state, the dynamometry initial value of six-dimension force sensor 2 is for robot 1：

Control machine people 1 does positive accelerated motion along tool coordinates system X-axis, and during which the acceleration at a certain moment is in coordinate system It is under OT-XTYTZT：

The unit vector of note robot 1 tool coordinates system X-direction isIt is represented by coordinate system OT-XTYTZT：

Assuming thatIt is represented by under the coordinate system OS-XSYSZS of six-dimension force sensor 2：

ThenIt is represented by under OS-XSYSZS：

Robot 1 moves the inertia force caused：

Wherein m is load quality.When robot 1 is moved, the power that six-dimension force sensor 2 is measured is by starting forceAnd inertia forceComposition, i.e.,：

And then obtain：

Due toIt is unit vector, then：

Similarly control machine people 1 does positive accelerated motion along tool coordinates system Y, Z axis, for the tool coordinates system of robot 1 Y, Z-direction unit vectorIt is represented by under the coordinate system of six-dimension force sensor 2：

It is by coordinate system OT-XTYTZT to coordinate system OS-XSYSZS rotation transition matrix then：

So just complete the demarcation of the Installation posture of six-dimension force sensor 2 pass.

The principle of the present invention is explained above, is moved by control machine people along the reference axis of its own, due in motion Inertia force, cause each axle reading of six-dimension force sensor to change, so as to be calibrated by corresponding sensor reading The direction relationses of robot corresponding axis and sensor coordinates axle, realize that sensor coordinate system and robot coordinate system's is relative Posture is demarcated.

Although the embodiment to the present invention gives detailed description and illustrated above, it should be noted that Those skilled in the art can carry out various equivalent changes and modification, its institute according to the spirit of the present invention to above-mentioned embodiment The function of generation, all should be within the scope of the present invention in the spirit covered without departing from specification and accompanying drawing.

Claims (3)

1. industrial robot end six-dimension force sensor Installation posture scaling method, comprises the following steps：

1) workpiece with certain mass is fixedly installed in six-dimension force sensor tool ends end, in the inactive state of industrial robot Under, the force data of three axles of six-dimension force sensor is read, as initial value, wherein：

2) control industrial robot does positive accelerated motion along tool coordinates system X-axis, during which gathers six-dimension force sensor dataCalculating obtains unit vector of the robot tool coordinate system X-axis under six-dimension force sensor coordinate system：

$\stackrel{\→}{e_x}=-\frac{{\left[\begin{array}{ccc}{F}_x-F_{x0}& F_y-F_{y0}& F_z-F_{z0}\end{array}\right]}^T}{\sqrt{{(F_x-F_{x0})}^2+{(F_y-F_{y0})}^2+{(F_z-F_{z0})}^2}}---\left(2\right);$

3) control industrial robot does positive accelerated motion along tool coordinates system Y-axis, during which gathers six-dimension force sensor dataCalculating obtains unit vector of the robot tool coordinate system Y-axis under six-dimension force sensor coordinate system For：

$\stackrel{\→}{e_y}=-\frac{{\left[\begin{array}{ccc}{F}_x-F_{x0}& F_y-F_{y0}& F_z-F_{z0}\end{array}\right]}^T}{\sqrt{{(F_x-F_{x0})}^2+{(F_y-F_{y0})}^2+{(F_z-F_{z0})}^2}}---\left(3\right);$

4) control industrial robot does positive accelerated motion along tool coordinates system Z axis, during which gathers six-dimension force sensor dataCalculating obtains unit vector of the robot tool coordinate system Z axis under six-dimension force sensor coordinate system For：

$\stackrel{\→}{e_z}=-\frac{{\left[\begin{array}{ccc}{F}_x-F_{x0}& F_y-F_{y0}& F_z-F_{z0}\end{array}\right]}^T}{\sqrt{{(F_x-F_{x0})}^2+{(F_y-F_{y0})}^2+{(F_z-F_{z0})}^2}}---\left(4\right);$

5) by step 2), result of calculation 3), 4), obtain being tied to the appearance of six-dimension force sensor coordinate system by robot tool coordinate State transformation matrix：

$R=\[\begin{array}{ccc}\stackrel{\→}{e_x}& \stackrel{\→}{e_y}& \stackrel{\→}{e_z}\end{array}\]---\left(5\right);$

It is that robot tool coordinate can be achieved to be tied to posture between six-dimension force sensor coordinate system using the posture changing matrix Mutually conversion, demarcation is so far completed.

2. the method for claim 1, wherein the robot is the 6DOF industrial robot of tandem.

3. the method for claim 1, wherein control machine people does positive accelerated motion along tool coordinates system X-axis, it is assumed that The acceleration at period at a certain moment is expressed as under robot tool coordinate system：

$\stackrel{\→}{a}={\left[\begin{array}{ccc}{a}_x& 0& 0\end{array}\right]}^T---\left(6\right)$

ThenIt is expressed as under six-dimension force sensor coordinate system：

$\stackrel{\→}{a_S}=a_x\·\stackrel{\→}{a_x}---\left(7\right)$

Assuming that the load quality at six-dimension force sensor sensitivity end is m, then the load inertia power that robot accelerated motion is brought is：

$\stackrel{\→}{F_c}=-m\stackrel{\→}{a_S}=-m\·a_{2x}\·\stackrel{\→}{e_x}---\left(8\right)$

During robot motion, the power that six-dimension force sensor is measured is by starting forceAnd inertia forceComposition, i.e.,：

$\stackrel{\→}{F}=\stackrel{\→}{F_0}+\stackrel{\→}{F_S}={\left[\begin{array}{ccc}{F}_{x0}& F_{y0}& F_{z0}\end{array}\right]}^T-{\mathrm{ma}}_{2x}\·\stackrel{\→}{e_x}---\left(9\right)$

Then obtain：

$\stackrel{\→}{e_x}=-\frac{{\left[\begin{array}{ccc}{F}_x-F_{x0}& F_y-F_{y0}& F_z-F_{z0}\end{array}\right]}^T}{{\mathrm{ma}}_{2x}}---\left(10\right).$