CN105783722A - Distance sensor method vector measurement method based on tetrahedron configuration - Google Patents

Abstract

The present invention provides a distance sensor method vector measurement method based on tetrahedron configuration. Three laser distance measuring sensors arranged in an equilateral triangle mode are installed on the end effector of a machine tool and a robot, and the end effector of the machine tool and the robot are configured to fix the measurement directions of the three laser distance measuring sensors, so that the laser beam is gathered into the same point and the end effector of the machine tool and the robot and the three laser distance measuring sensors form a space tetrahedron; the three position relations of the space tetrahedron top and the curved surface to be measure are employed, the three position relations include: the top is located in the curved surface, the top is located on the curved surface, and the top is located out of the curved surface, the normal vector n of the manufacture hole curved surface to be measured is obtained through combining the numerical value measured by the laser distance measuring sensors; and finally, the driving amount of each shaft of the machine tool or the robot is obtained to allow the control system to perform the posture alignment motion according to the normal vector information of the manufacture hole to be measured obtained by the measurement and calculation. The distance sensor method vector measurement method based on tetrahedron configuration is high in solution precision and is able to effectively and rapidly respond to the requirements of the control system.

Description

A kind of range sensor method based on tetrahedral configuration vows measuring method

Technical field

The present invention relates to a kind of method and vow measurement technology, especially a kind of method for aircraft skin drilling vows measuring method, and specifically a kind of range sensor method based on tetrahedral configuration vows measuring method.

Background technology

Nearly 150～2,000,000 connecting holes on one frame large aircraft, aircaft configuration is mainly through realizing being mechanically connected in the riveted joint at this some holes place and being spirally connected.According to statistics, the 70% of airframe fatigue failure accident is derived from structural connection position, and wherein the fatigue crack of 80% results from connection hole.Securing member is connected use and is analyzed showing by Boeing, and when securing member is tilted more than 2 ° along external load function direction, fatigue life reduces about 47%；When being tilted more than 5 °, fatigue life reduces by 95%, it will thus be seen that connecting hole quality strong influence the life-span of aircraft.Therefore, for ensureing aircraft assembling quality, improving the fatigue life of body, increasing automation equipment is used in the assembling process of large aircraft, such as automatic drill riveter, flexible rail drilling mechanism, climbing robot drilling mechanism and mechanical arm drilling mechanism etc..

In automation equipment drilling process, the perpendicularity in hole depends on whether drill axis overlaps with the normal of drilling point.At present, equipment is difficult to lean on the direction of normal boring self controlling to make drill bit along boring point, it is necessary to utilizes method to vow and measures with end posture adjusting device to adjust the attitude of drill bit.Method for curved surface vows measurement, common are vector cross product method, conicoid fitting, nurbs curve method and Triangular meshes method etc..Above method is when engineer applied, it is necessary to measures substantial amounts of point and can be only achieved higher precision, is not suitable for real-time accurate measurement.

The present invention is directed to the problem appeared above and propose the eyes with non-contact method arrow measuring method of a kind of three laser range sensors based on tetrahedral configuration, the method certainty of measurement is high, speed is fast, and will not damage testee surface.

Summary of the invention

It is an object of the invention to vow that the precision existed in measuring method is not high for existing method, the problem of poor real, inventing a kind of range sensor method based on tetrahedral configuration and vow measuring method, it is measured by three laser range sensors quickly realizing of realizing the hole method of aircraft skin drilling is vowed.

The technical scheme is that

A kind of range sensor method based on tetrahedral configuration vows measuring method, it is characterized in that it comprises the following steps:

First, the end effector of lathe or robot is installed three laser range sensors arranged in equilateral triangle, and fix the measurement direction of three laser range sensors so that its laser beam converges at same point, constitute a space tetrahedron with three laser range sensors；

Secondly, utilize three kinds of position relationships of space tetrahedron top and curved surface to be measured: summit in curved surface, summit on curved surface, summit outside curved surface, in conjunction with the numerical value that laser range sensor is measured, it is possible to try to achieve the method arrow n of drilling curved surface to be measured；

Finally, vow information according to the drilling method for the treatment of that above-mentioned survey calculation is obtained, by anti-resolving Algorithm, try to achieve the drive volume of each axle of lathe or robot, be used for controlling system and realize posture adjustment campaign.

So that the measurement result of drilling surface normal vector n to be measured is more accurate, make following constraint: l_min≤l_i≤l_max

(i=1,2,3)

L in formula_iIt is three laser range sensor laser emission point distances to drilling curved surface to be measured, l_minAnd l_maxRespectively meet drilling method and vow l during required precision_iMinimum range and ultimate range, its concrete numerical value can by the distance of laser range sensor laser emission point to laser beam convergent point and treat that the accuracy class that drilling method is vowed is obtained.Work as l_iAfter meeting above-mentioned constraint, the method for drilling curved surface to be measured vows that n specifically can solve according to following three kinds of situations.

Situation one: tetrahedron top is in curved surface to be measured

When space tetrahedron and position to be detected place surface intersection, setting up coordinate system as shown in Figure 2, zero is based upon cutter end points, 3 described laser range sensors A, B, C are that equilateral triangle is distributed in cutter surrounding, set x_tDirection was O_tPoint is parallel to AB and is pointed to B direction, y by A_tDirection is O_tC direction, z_tDirection obtains according to right hand theorem.First, according to design and installation, it is determined that the installation site of 3 laser range sensors, and 3 laser of 3 laser range sensors are made to converge at 1 D, namely, before surface normal vector is measured by laser range sensor, ensure that tetrahedron D-ABC configuration is known by frame for movement and assembling.Then A, B, C are at O_tx_ty_tz_tCoordinate under coordinate system is respectivelyC(0,CD·cos∠DCO_t, 0),

When place, position to be detected, curved surface intersects with tetrahedron, can be in the hope of according to geometrical relationship

A₁(-A₁D·cos∠DAO_t·cos∠O_tAB,-A₁D·cos∠DAO_t·sin∠O_tAB,AA₁·sin∠DAO_t)

B₁(B₁D·cos∠DBO_t·cos∠O_tBA,1B₁D·cos∠DBO_t·sin∠O_tBA,BB₁·sin∠DBO_t)

C₁(0,DC₁·cos∠DCO_t,CC₁·sinDCO_t)

Make A₁(x_a1,y_a1,z_a1), B₁(x_b1,y_b1,z_b1), C₁(x_c1,y_c1,z_c1), then A₁B₁(x_b1-x_a1,y_b1-y_a1,z_b1-z_a1), A₁C₁(x_c1-x_a1,y_c1-y_a1,z_c1-z_a1), B₁C₁(x_b1-x_c1,y_b1-y_c1,z_b1-z_c1), if plane A₁B₁C₁Normal direction coordinate be (l₁,m₁,n₁), then, and the definition according to normal vector

Pass through above formula, it is possible to solve (l₁,m₁,n₁), wherein n₁It is hole site to be processed law vector.

Situation two: summit is on curved surface

When tetrahedron top overlaps with place, position to be detected curved surface, as shown in the figure.It is believed that A₁, B₁, C₁3 overlap with D point, namely

By situation one Chinese style (1), (l solved₁,m₁,n₁) there is an infinite multiple combination, therefore two times hole site to be processed law vector unsolvables of situation.

Situation three: summit is outside curved surface

When place, position to be detected surface intersection is on the extended line of space tetrahedron top, as it can be seen, can be in the hope of according to geometrical relationship

A₂(DA₂·cos∠DAO_t·cos∠O_tAB,DA₂·cos∠DAO_t·sin∠O_tAB,AA₂·sin∠DAO_t)

B₂(-DB₂·cos∠DBO_t·cos∠O_tBA,DB₂·cos∠DBO_t·sin∠O_tBA,BB₂·sin∠DBO_t)

C₂(0,-DC₂·cos∠DCO_t,CC₂·sinDCO_t)

Make A₂(x_a2,y_a2,z_a2), B₂(x_b2,y_b2,z_b2)C₂(x_c2,y_c2,z_c2), then A₂B₂(x_b2-x_a2,y_b2-y_a2,z_b2-z_a2), A₂C₂(x_c2-x_a2,y_c2-y_a2,z_c2-z_a2), B₂C₂(x_b2-x_c2,y_b2-y_c2,z_b2-z_c2), if plane A₂B₂C₂Normal direction coordinate be (l₂,m₂,n₂), then, and the definition according to normal vector

By above formula (3), it is possible to solve (l₂,m₂,n₂), wherein n₂It is hole site to be processed law vector.

The invention has the beneficial effects as follows:

The inventive method is simple, and the data recorded by the geometrical relationship based on tetrahedral configuration arranged in advance and laser range sensor can be realized the method to hole to be processed and vow measurement.Again through anti-resolving Algorithm, it is possible to realize lathe or robot are realized the drive volume of each axle of drilling processing very easily, be used for controlling system and realize posture adjustment campaign.Therefore, the present invention has solving precision height, can efficiently and rapidly respond the demand of control system.

Accompanying drawing explanation

The method that Fig. 1 is the present invention vows measurement procedure.

Fig. 2 is that the tetrahedron top of present invention method arrow in curved surface to be measured solves schematic diagram.

Fig. 3 is that the tetrahedron top of present invention method arrow on curved surface solves schematic diagram.

Fig. 4 is that the tetrahedron top of present invention method arrow outside curved surface to be measured solves schematic diagram.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is further illustrated.

Referring to the accompanying drawing illustrating the embodiment of the present invention, the present invention is described in more detail.But, the present invention can realize in many different forms, and should not be construed as by restriction of the embodiment of proposition at this.On the contrary, it is proposed to these embodiments be for abundant and complete disclosure, and make those skilled in the art understand the scope of the present invention completely.

As Figure 1-4, a kind of range sensor method based on tetrahedral configuration vows measuring method, and it comprises the following steps:

First, before carrying out part method to be processed arrow measurement, mounted three laser range sensors are carried out precision calibration, adjusts the assembly precision of laser range sensor, make three laser range sensors converge at same point, namely constitute a tetrahedron.

Secondly, the tetrahedron constituted due to three laser range sensors pre-set size in space is limited, and laser range sensor certainty of measurement is inverse ratio with measurement distance, therefore, drive lathe or robot, make laser measurement sensor tentatively realize method arrow with part to be detected to be directed at, and adjust to suitable distance, meet distance constraints.

3rd, utilize the value that three laser range sensors are surveyed, carry out the selection of method vector calculus method, if the tetrahedron top of the formation of three laser range sensors is just at part surface to be measured, then end effector is finely tuned；If summit is below part to be measured, then selection algorithm one realizes treating the calculating that machined surface method is vowed；If summit is above part to be measured, then selection algorithm two realizes treating the calculating that machined surface method is vowed.

Finally, vow information according to computed to be processed the method obtained of above-mentioned measurement, by inverse kinematic algorithm, obtain lathe or robot arrives each axle drive volume that drilling method is vowed, be used for controlling system and realize posture adjustment campaign.

Details are as follows:

Setting up coordinate system as depicted, zero is based upon cutter end points, 3 described laser range sensors A, B, C are that equilateral triangle is distributed in cutter surrounding, set x_tDirection was O_tPoint is parallel to AB and is pointed to B direction, y by A_tDirection is O_tC direction, z_tDirection obtains according to right hand theorem.First, according to design and installation, it is determined that the installation site of 3 laser range sensors, and 3 laser of 3 laser range sensors are made to converge at 1 D, namely, before surface normal vector is measured by laser range sensor, ensure that tetrahedron D-ABC configuration is known by frame for movement and assembling.Then A, B, C are at O_tx_ty_tz_tCoordinate under coordinate system is respectively C(0,CD·cos∠DCO_t, 0),

When place, position to be detected, curved surface intersects with tetrahedron, can be in the hope of according to geometrical relationship

A₁(-A₁D·cos∠DAO_t·cos∠O_tAB,-A₁D·cos∠DAO_t·sin∠O_tAB,AA₁·sin∠DAO_t)

B₁(B₁D·cos∠DBO_t·cos∠O_tBA,1B₁D·cos∠DBO_t·sin∠O_tBA,BB₁·sin∠DBO_t)

C₁(0,DC₁·cos∠DCO_t,CC₁·sinDCO_t)

Make A₁(x_a1,y_a1,z_a1), B₁(x_b1,y_b1,z_b1)C₁(x_c1,y_c1,z_c1), then A₁B₁(x_b1-x_a1,y_b1-y_a1,z_b1-z_a1), A₁C₁(x_c1-x_a1,y_c1-y_a1,z_c1-z_a1), B₁C₁(x_b1-x_c1,y_b1-y_c1,z_b1-z_c1), if plane A₁B₁C₁Normal direction coordinate be (l₁,m₁,n₁), then, and the definition according to normal vector

By above formula (4), it is possible to solve (l₁,m₁,n₁), wherein n₁It is hole site to be processed law vector.

When place, position to be detected curved surface and tetrahedron are non-intersect, can be in the hope of according to geometrical relationship

A₂(DA₂·cos∠DAO_t·cos∠O_tAB,DA₂·cos∠DAO_t·sin∠O_tAB,AA₂·sin∠DAO_t)

B₂(-DB₂·cos∠DBO_t·cos∠O_tBA,DB₂·cos∠DBO_t·sin∠O_tBA,BB₂·sin∠DBO_t)

C₂(0,-DC₂·cos∠DCO_t,CC₂·sinDCO_t)

Make A₂(x_a2,y_a2,z_a2), B₂(x_b2,y_b2,z_b2)C₂(x_c2,y_c2,z_c2), then A₂B₂(x_b2-x_a2,y_b2-y_a2,z_b2-z_a2), A₂C₂(x_c2-x_a2,y_c2-y_a2,z_c2-z_a2), B₂C₂(x_b2-x_c2,y_b2-y_c2,z_b2-z_c2), if plane A₂B₂C₂Normal direction coordinate be (l₂,m₂,n₂), then, and the definition according to normal vector

By above formula (5), it is possible to solve (l₂,m₂,n₂), wherein n₂It is hole site to be processed law vector.

Although describing the specific embodiment of the present invention above, it will be appreciated by those of skill in the art that these are merely illustrative of, protection scope of the present invention is defined by the appended claims.Those skilled in the art is under the premise without departing substantially from principles of the invention and essence, it is possible to these embodiments are made various changes or modifications, but these change and amendment all falls within protection scope of the present invention.

Claims (4)

1. vow a measuring method based on the range sensor method of tetrahedral configuration, it is characterized in that it comprises the following steps:

First, the end effector of lathe or robot is installed three laser range sensors arranged in equilateral triangle, and fix the measurement direction of three laser range sensors, make its laser beam converge at same point, three laser range sensors and described convergent point collectively form a space tetrahedron；Zero is based upon cutter tips point, and three laser range sensors are that equilateral triangle is distributed in cutter surrounding；

Secondly, utilize three kinds of position relationships of space tetrahedron top and curved surface to be measured: summit in curved surface, summit on curved surface, summit outside curved surface, in conjunction with the numerical value that laser range sensor is measured, try to achieve the method arrow n treating drilling central point on drilling curved surface to be measured；

Finally, vow information according to the method treating drilling central point that above-mentioned survey calculation is obtained, by anti-resolving Algorithm, try to achieve the drive volume of each axle of lathe or robot, be used for controlling system and realize posture adjustment campaign, make tool axis and vow consistent with the method tried to achieve.

2. method according to claim 1, is characterized in that: so that the measurement result of drilling surface normal vector n to be measured is more accurate, make following constraint: l_min≤l_i≤l_max(i=1,2,3)

L in formula_iIt is three laser range sensor laser emission point distances to drilling curved surface to be measured, l_minAnd l_maxRespectively meet drilling method and vow l during required precision_iMinimum range and ultimate range, its concrete numerical value can by the distance of laser range sensor laser emission point to laser beam convergent point and treat that the accuracy class that drilling method is vowed is obtained.Work as l_iAfter meeting above-mentioned constraint, the method for drilling curved surface to be measured vows that n specifically can solve according to following three kinds of situations.

3. method according to claim 1, is characterized in that when tetrahedron top is in curved surface to be measured, sets x_tDirection was zero O_tPoint is parallel to AB and is pointed to B direction, y by A_tDirection is O_tC direction, z_tDirection obtains according to right hand theorem；First, according to design and installation, it is determined that the installation site of 3 laser range sensors, and 3 laser of 3 laser range sensors are made to converge at 1 D, namely, before surface normal vector is measured by laser range sensor, ensure that tetrahedron D-ABC configuration is known by frame for movement and assembling；Then A, B, C are at O_tx_ty_tz_tCoordinate under coordinate system is respectivelyC(0_,CD·cos∠DCO_t, 0),

When place, position to be detected, curved surface intersects with tetrahedron, can be in the hope of according to geometrical relationship:

A₁(-A₁D·cos∠DAO_t·cos∠O_tAB,-A₁D·cos∠DAO_t·sin∠O_tAB,AA₁·sin∠DAO_t)

B1(B₁D·cos∠DBO_t·cos∠O_tBA_,1B₁D·cos∠DBO_t·sin∠O_tBA_,BB₁·sin∠DBO_t)

C₁(0,DC₁·cos∠DCO_t,CC₁·sinDCO_t)

Make A₁(x_a1,y_a1,z_a1), B₁(x_b1,y_b1,z_b1), C₁(x_c1,y_c1,z_c1), then A₁B₁(x_b1-x_a1,y_b1-y_a1,z_b1-z_a1), A₁C₁(x_c1-x_a1,y_c1-y_a1,z_c1-z_a1), B₁C₁(x_b1-x_c1,y_b1-y_c1,z_b1-z_c1), if plane A₁B₁C₁Normal direction coordinate be (l₁,m₁,n₁), then, and the definition according to normal vector

$\{\begin{array}{c}(x_{b1}-x_{a1})\·l_1+(y_{b1}-y_{a1})\·m_1+(z_{b1}-z_{a1})\·n_1=0\\ (x_{c1}-x_{a1})\·l_1+(y_{c1}-y_{a1})\·m_1+(z_{c1}-z_{a1})\·n_1=0\\ (x_{b1}-x_{c1})\·l_1+(y_{b1}-y_{c1})\·m_1+(z_{b1}-z_{c1})\·n_1=0\end{array}---\left(1\right)$

Pass through above formula, it is possible to solve (l₁,m₁,n₁), wherein n₁It is hole site to be processed law vector.

4. method according to claim 1, is characterized in that tetrahedron top is outside curved surface, when place, position to be detected surface intersection is on the extended line of space tetrahedron top, and can be in the hope of according to geometrical relationship:

A₂(DA₂·cos∠DAO_t·cos∠O_tAB_,DA₂·cos∠DAO_t·sin∠O_tAB_,AA₂·sin∠DAO_t)

B₂(-DB₂·cos∠DBO_t·cos∠O_tBA_,DB₂·cos∠DBO_t·sin∠O_tBA_,BB₂·sin∠DBO_t)

C₂(0,-DC₂·cos∠DCO_t,CC₂·sinDCO_t)

Make A₂(x_a2,y_a2,z_a2), B₂(x_b2,y_b2,z_b2)C₂(x_c2,y_c2,z_c2), then A₂B₂(x_b2-x_a2,y_b2-y_a2,z_b2-z_a2), A₂C₂(x_c2-x_a2,y_c2-y_a2,z_c2-z_a2), B₂C₂(x_b2-x_c2,y_b2-y_c2,z_b2-z_c2), if plane A₂B₂C₂Normal direction coordinate be (l₂,m₂,n₂), then, and the definition according to normal vector

$\left\{\begin{array}{c}(x_{b2}-x_{a2})\·l_2+(y_{b2}-y_{a2})\·m_2+(z_{b2}-z_{a2})\·n_2=0\\ (x_{c2}-x_{a2})\·l_2+(y_{c2}-y_{a2})\·m_2+(z_{c2}-z_{a2})\·n_2=0\\ (x_{b2}-x_{c2})\·l_2+(y_{b2}-y_{c2})\·m_2+(z_{b2}-z_{c2})\·n_2=0\end{array}\right.---\left(3\right)$

By above formula (3), it is possible to solve (l₂,m₂,n₂), wherein n₂It is hole site to be processed law vector.