CN103707298B - The evaluation method of a kind of continuous type robot space path tracking effect - Google Patents

Abstract

The evaluation method of a kind of continuous type robot space path tracking effect.It comprises sets up the evaluation index stage and follows the tracks of calculation stages, setting up the evaluation index stage is first set up path trace Performance Evaluating Indexes: worst error, mean error, response time and control accuracy, tracking calculation stages comprises sets up snake arms end joint branch, ask branch path coordinate, set up path branch array, follow the tracks of a path joint segments, determine whether the first joint segments, ask the first joint segments branch distance, ask branch to the distance in path, calculate maximum range value, the recording responses time, judge whether path trace, determine worst error value, determine mean error, determine the stages such as control accuracy: continuous type robot path tracking effect evaluation method provided by the invention can objective description follow the tracks of situation, there is time complexity low, be easy to the feature of software simulating.

Description

The evaluation method of a kind of continuous type robot space path tracking effect

Technical field

The invention belongs to automatic control technology field, particularly relate to the evaluation method of a kind of continuous type robot space path tracking effect.

Background technology

Continuous type robot is a kind of Novel bionic robot adopting " without vertebra " flexible structure, there is good bending property, can be submissive and change self shape neatly, its excellent flexural property even can match in excellence or beauty with biologic-organs such as snake, trunk and octopus feelers.Because the profile of continuous type robot can change flexibly, therefore there is the situation of environmentally barrier and change the ability of own form, to the environment of limited working space, there is unique adaptive capacity.It has a extensive future, and can be applied to the occasion such as the operation in fuel tanker inspection, multi-obstacle avoidance industrial environment, crooked pipeline and the investigation of subsiding in building and search and rescue, the maintenance of nuclear power station internal duct, the diagnosis and treatment of human body diseases.

Continuous type robot is the serial manipulator be made up of multiple joint segments, and its joint segments has structural constraint, can carry out the bending of space and rotary motion.In the very strong environment of space structure constraint, touch for avoiding robot and cause damage or potential danger, need the travel path that robot arrives target area be planned.Path is be made up of the curve in several similar continuous type joints, meets its structural constraint, is the final carriage that continuous type robot arrives target area.When designing track algorithm, being analysis and inspection tracking effect, needing to propose evaluation method.And the current evaluation for continuous type robotic tracking effect still lacks foundation.

Under this technical background, not yet find the evaluation method being directed to continuous type robot space path tracking effect at present.

Summary of the invention

In order to solve the problem, the object of the present invention is to provide the evaluation method of a kind of continuous type robot space path tracking effect.

In order to achieve the above object, the evaluation method of continuous type robot provided by the invention space path tracking effect comprise set up the evaluation index stage and follow the tracks of calculation stages;

(1) the evaluation index stage is set up

First path trace Performance Evaluating Indexes is set up: worst error, mean error, response time and control accuracy;

(2) calculation stages is followed the tracks of

In each step of the stepping process of snake arms track path, calculate the parameters also required for records appraisal index, after tracking completes, determine every numerical value of evaluation index.

Setting up in the evaluation index stage, described evaluation index comprises:

1.1) worst error

Worst error refers to that continuous type robot snake arms is in the maximum deviation distance to snake arms joint segments and respective paths section during path trace; Owing to only solving the joint segments variable of snake arms end joint segments in track path process, all the other joint segments repeat the motion of snake arms end joint segments, therefore after each stepping of snake arms pedestal, the ultimate range in a demand solution end joint segments and path, the maximum in these ultimate ranges is worst error; Joint, path hop count is n, if ultimate range is d _maxt(t=1,2,3 ..., nw), worst error is e _max;

1.2) mean error

Mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\‾}{e}=\frac{\underset{t=1}{\overset{\mathrm{nw}}{\mathrm{\Σ}}}{d}_{\max t}}{\mathrm{nw}}$

1.3) response time

Response time refers to the time at every turn calculated needed for snake arms joint segments variable, is used for weighing the rapidity of control algolithm;

1.4) control accuracy

Control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to path planning algorithm after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point.

The specific operation process of described tracking calculation stages comprise perform in order as the next stage:

Step one, set up S01 stage of snake arms end joint branch: snake arms end joint segments is divided into w part;

Step 2, ask branch path coordinate { B ₀the S02 stage: solve branch at path coordinate system { B ₀in coordinate, be denoted as array U (q) (q=1,2 ..., w);

Step 3, set up path branch array { V _p,qthe S03 stage: each for path joint segments is divided equally w part, branch form array V (p, q) (p=1,2 ..., n; Q=1,2 ..., w);

The S04 stage of step 4, a tracking path joint segments: snake arms takes a step forward, and completes the action of track path; That is: snake arms end joint segments track path joint segments, pedestal jth (0≤j≤w) secondary stepping;

Step 5, determine whether S05 stage of the first joint segments: judge that whether the tracing object of current snake arms end joint segments is first joint segments in path, if judged result is "Yes", then enter next step S06 stage, otherwise next step enters the S07 stage;

Step 6, ask the S06 stage of the first joint segments branch distance: determine branch distance during track path the first joint segments, calculate j point after in array U (q) respectively and arrive array V (1, q) in distance a little, get minimum of a value as the distance of the point in snake arms to path, the maximum in these distance values is this time to the ultimate range d in path _maxt;

Step 7, ask branch to the S07 stage of the distance in path: during track path m joint segments (1<m≤n), to need to calculate in array U (q) each point to array V (m-1, q) with V (m, q) in distance a little, get minimum of a value as the approximation of this point to path distance, be similar to and think that its minimum of a value is the distance of this point to path;

In the S08 stage of step 8, calculating maximum range value: after each stepping of pedestal, obtain above-mentioned distance, be similar to and think that distance maximum is the ultimate range d in end joint segments and path _maxt,

In the S09 stage of step 9, recording responses time: the response time refers to the time at every turn calculated needed for snake arms joint segments variable, be used for weighing the rapidity of computational process;

Step 10, judge whether S10 stage of path trace: judge whether current snake arms end reaches the end in path, if judged result is "Yes", then enter next step S11 stage, otherwise next step reenters the S04 stage, continue step trakcing;

Step 11, determine S11 stage of worst error value: worst error is the maximum in ultimate range;

Worst error e _maxfor:

e _max=max{d _max1,d _max2,...,d _maxt}

Step 12, determine S12 stage of mean error: mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\&OverBar;}{e}=\frac{\underset{t=1}{\overset{\mathrm{nw}}{\mathrm{\&Sigma;}}}{d}_{\max t}}{\mathrm{nw}}$

Step 13, determine S12 stage of control accuracy: control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to paths planning method after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point; This flow process so far terminates.

Continuous type robot path tracking effect evaluation method provided by the invention can objective description follow the tracks of situation, have the advantages that time complexity is low, be easy to software simulating.

Accompanying drawing explanation

Fig. 1: continuous type robot architecture schematic diagram.

Fig. 2: the evaluation method flow chart of continuous type robot provided by the invention space path tracking effect.

Fig. 3: solve ultimate range schematic diagram.

Fig. 4: continuous type robotic tracking three joint segments co planar pathway---emulation experiment figure.

Fig. 5: continuous type robotic tracking three joint segments co planar pathway error curve diagram.

Fig. 6: continuous type robotic tracking three joint segments space three-dimensional path schematic diagram.

Detailed description of the invention

Be described in detail below in conjunction with the evaluation method of the drawings and specific embodiments to continuous type robot provided by the invention space path tracking effect.

As shown in Figure 1, continuous type robot is a kind of submissive, Novel bionic robot that flexibility is high, is generally made up of compliant mechanism 1, telescoping mechanism 2, control system 3 and mobile platform 4, due to the similar sinuous snake of compliant mechanism 1, referred to herein as snake arms; Snake arms is generally the serial mechanism of multiple construction unit composition, and each construction unit is called joint segments, has rotation with bending θ two frees degree, be called joint segments variable.Telescoping mechanism 2 has one degree of freedom, can realize the precise motion of one dimension, and the hoistable platform at telescoping mechanism 2 top is called pedestal, and it is advanced for snake arms and provides basis.Control system 3 is the core controlled, and realizes the trajectory path planning to snake arms, path following control and detection signal process and teletransmission.

As shown in Figure 2, the evaluation method of continuous type robot provided by the invention space path tracking effect comprise set up the evaluation index stage and follow the tracks of calculation stages;

(1) the evaluation index stage is set up

For better evaluating the effect of tracking, first set up path trace Performance Evaluating Indexes: worst error, mean error, response time and control accuracy;

1.1) worst error

Worst error refers to that continuous type robot snake arms is in the maximum deviation distance to snake arms joint segments and respective paths section during path trace; Owing to only solving the joint segments variable of snake arms end joint segments in track path process, all the other joint segments repeat the motion of snake arms end joint segments, therefore after each stepping of snake arms pedestal, the ultimate range in a demand solution end joint segments and path, the maximum in these ultimate ranges is worst error; Joint, path hop count is n, if ultimate range is d _maxt(t=1,2,3 ..., nw), worst error is e _max;

1.2) mean error

Mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\&OverBar;}{e}=\frac{\underset{t=1}{\overset{\mathrm{nw}}{\mathrm{\&Sigma;}}}{d}_{\max t}}{\mathrm{nw}}---\left(1\right)$

1.3) response time

Response time refers to the time at every turn calculated needed for snake arms joint segments variable, is used for weighing the rapidity of control algolithm;

1.4) control accuracy

Control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to path planning algorithm after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point;

(2) calculation stages is followed the tracks of

In each step of the stepping process of snake arms track path, calculate the parameters also required for records appraisal index, after tracking completes, determine every numerical value of evaluation index; Its process comprises as the next stage:

Step one, set up S01 stage of snake arms end joint branch: snake arms end joint segments is divided into w part;

Step 2, ask branch path coordinate { B ₀the S02 stage: solve branch at path coordinate system { B ₀in coordinate, be denoted as array U (q) (q=1,2 ..., w);

Step 3, set up path branch array { V _p,qthe S03 stage: each for path joint segments is divided equally w part, branch form array V (p, q) (p=1,2 ..., n; Q=1,2 ..., w);

The S04 stage of step 4, a tracking path joint segments: snake arms takes a step forward, and completes the action of track path; That is: snake arms end joint segments track path joint segments, pedestal jth (0≤j≤w) secondary stepping;

Step 5, determine whether S05 stage of the first joint segments: judge that whether the tracing object of current snake arms end joint segments is first joint segments in path, if judged result is "Yes", then enter next step S06 stage, otherwise next step enters the S07 stage;

Step 6, ask the S06 stage of the first joint segments branch distance: determine branch distance during track path the first joint segments, calculate j point after in array U (q) respectively and arrive array V (1, q) in distance a little, get minimum of a value as the distance of the point in snake arms to path, the maximum in these distance values is this time to the ultimate range d in path _maxt;

Step 7, ask branch to the S07 stage of the distance in path: during track path m joint segments (1<m≤n), to need to calculate in array U (q) each point to array V (m-1, q) and in V (m, q) distance a little; Fig. 3 is for solving ultimate range schematic diagram, Fig. 3 (a) is for a bit arriving each branch distance of path first joint segments in snake arms end joint segments, get minimum of a value as the approximation of this point to path distance, Fig. 3 (b), for a branch in snake arms end joint segments during track path second joint section is to the distance of each branch of path two joint section, is similar to and thinks that its minimum of a value is the distance of this point to path;

In the S08 stage of step 8, calculating maximum range value: after each stepping of pedestal, obtain above-mentioned distance, be similar to and think that distance maximum is the ultimate range d in end joint segments and path _maxt,

In the S09 stage of step 9, recording responses time: the response time refers to the time at every turn calculated needed for snake arms joint segments variable, be used for weighing the rapidity of computational process;

Step 10, judge whether S10 stage of path trace: judge whether current snake arms end reaches the end in path, if judged result is "Yes", then enter next step S11 stage, otherwise next step reenters the S04 stage, continue step trakcing;

Step 11, determine S11 stage of worst error value: worst error is the maximum in ultimate range;

Worst error e _maxfor:

e _max=max{d _max1,d _max2,...,d _maxt}(2)；

Step 12, determine S12 stage of mean error: mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\&OverBar;}{e}=\frac{\underset{t=1}{\overset{\mathrm{nw}}{\mathrm{\&Sigma;}}}{d}_{\max t}}{\mathrm{nw}}---\left(3\right);$

Step 13, determine S12 stage of control accuracy: control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to paths planning method after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point; This flow process so far terminates.

The operational effect of the evaluation method of continuous type robot provided by the invention space path tracking effect:

Use MATLAB to carry out emulation experiment, in experiment, provide the joint segments number after path planning and each joint segments variable; Choose single joint segments length L=50cm, pedestal step value s=1cm; Table 1 is simple joint section path trace experimental data, and along with joint segments angle of bend increases, worst error and mean error increase gradually; Table 2 is the tracking test data in three joint segments paths when the anglec of rotation is 0 °, and now, three joint segments are coplanar; Table 3 is three joint segments space path tracking test data, when the anglec of rotation is different, and two joint section antarafacial.

The path trace of table 1 simple joint section is tested

Table 2 three joint segments co planar pathway tracking test

The path trace of table 3 three joint space is tested

Can be obtained by experimental data, for different path, worst error and average error criterion can show the degree of deflection path in snake arms tracing process; Response time shows the rapidity of tracking; Control accuracy shows and impact point deviation size, and the degree of accuracy of tracking is described.

For verifying evaluation method effect provided by the invention, Figure 4 shows that the analogous diagram of tracking three joint segments co planar pathway, path joint segments variable is the 6th group of data in table 2; Fig. 4 (a), Fig. 4 (b) and Fig. 4 (c) are respectively track path first and second and three joint segments, snake arms joint segments distal point corresponding with path joint segments in tracing process approaches path, in Fig. 4 (c), the anglec of rotation of snake arms end joint segments is 180 °, Fig. 4 (d) for after tracking completes, snake arms and paths merge; Figure 5 shows that tracking three joint segments co planar pathway error curve diagram, circle represents snake arms at every turn to the ultimate range d in path _maxt, straight line is mean error ; Figure 6 shows that the analogous diagram in tracking three joint segments space three-dimensional path, path joint segments variable is second group of data in table 3; Fig. 6 (a), Fig. 6 (b) and Fig. 6 (c) are respectively track path first and second and three joint segments, Fig. 6 (d) figure is for completing path trace, snake arms and paths merge, Fig. 6 (e) is the swept area of space of snake arms in tracing process, can find out snake arms in tracing process all the time near path.

Claims (3)

1. an evaluation method for continuous type robot space path tracking effect, is characterized in that: it comprises sets up the evaluation index stage and follows the tracks of calculation stages;

(1) the evaluation index stage is set up

First path trace Performance Evaluating Indexes is set up: worst error, mean error, response time and control accuracy; Worst error refers to that continuous type robot snake arms is in the maximum deviation distance to snake arms joint segments and respective paths section during path trace; Mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments; Response time refers to the time at every turn calculated needed for snake arms joint segments variable; Control accuracy has referred to the distance of snake arms distal point and path ends point after path trace;

(2) calculation stages is followed the tracks of

In each step of the stepping process of snake arms track path, calculate the parameters also required for records appraisal index, after tracking completes, determine every numerical value of evaluation index.

2. the evaluation method of continuous type robot according to claim 1 space path tracking effect, is characterized in that: setting up in the evaluation index stage, described evaluation index comprises:

1.1) worst error

Worst error refers to that continuous type robot snake arms is in the maximum deviation distance to snake arms joint segments and respective paths section during path trace; Owing to only solving the joint segments variable of snake arms end joint segments in track path process, all the other joint segments repeat the motion of snake arms end joint segments, therefore after each stepping of snake arms pedestal, the ultimate range in a demand solution end joint segments and path, the maximum in these ultimate ranges is worst error; Joint, path hop count is n, if ultimate range is d _maxt, wherein t=1,2,3 ..., nw, worst error is e _max;

1.2) mean error

Mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\&OverBar;}{e}=\frac{\underset{t=1}{\overset{nw}{\&Sigma;}}{d}_{\max t}}{nw}$

Wherein w represents the number that snake arms end joint segments is divided equally;

1.3) response time

Response time refers to the time at every turn calculated needed for snake arms joint segments variable, is used for weighing the rapidity of control algolithm;

1.4) control accuracy

Control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to path planning algorithm after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point.

3. the evaluation method of continuous type robot according to claim 1 space path tracking effect, is characterized in that: the specific operation process of described tracking calculation stages comprise perform in order as the next stage:

Step one, set up S01 stage of snake arms end joint branch: snake arms end joint segments is divided into w part;

Step 2, ask branch path coordinate { B ₀the S02 stage: solve branch at path coordinate system { B ₀in coordinate, be denoted as array U (q), wherein q=1,2 ..., w;

Step 3, set up path branch array { V _p,qthe S03 stage: each for path joint segments is divided equally w part, branch form array V (p, q), wherein p=1,2 ..., n; Q=1,2 ..., w;

The S04 stage of step 4, a tracking path joint segments: snake arms takes a step forward, and completes the action of track path; That is: snake arms end joint segments track path joint segments, time stepping of pedestal jth, wherein 0≤j≤w;

Step 5, determine whether S05 stage of the first joint segments: judge that whether the tracing object of current snake arms end joint segments is first joint segments in path, if judged result is "Yes", then enter next step S06 stage, otherwise next step enters the S07 stage;

Step 6, ask the S06 stage of the first joint segments branch distance: determine branch distance during track path the first joint segments, calculate j point after in array U (q) respectively and arrive array V (1, q) in distance a little, get minimum of a value as the distance of the point in snake arms to path, the maximum in these distance values is this time to the ultimate range d in path _maxt;

Step 7, ask branch to the S07 stage of the distance in path: during track path m joint segments, wherein 1<m≤n, to need to calculate in array U (q) each point to array V (m-1, q) with V (m, q) in distance a little, get minimum of a value as the approximation of this point to path distance, be similar to and think that its minimum of a value is the distance of this point to path;

In the S08 stage of step 8, calculating maximum range value: after each stepping of pedestal, obtain above-mentioned distance, be similar to and think that distance maximum is the ultimate range d in end joint segments and path _maxt,

In the S09 stage of step 9, recording responses time: the response time refers to the time at every turn calculated needed for snake arms joint segments variable, be used for weighing the rapidity of computational process;

Step 10, judge whether S10 stage of path trace: judge whether current snake arms end reaches the end in path, if judged result is "Yes", then enter next step S11 stage, otherwise next step reenters the S04 stage, continue step trakcing;

Step 11, determine S11 stage of worst error value: worst error is the maximum in ultimate range;

Worst error e _maxfor:

e _max＝max{d _max1,d _max2,…,d _maxt}

Step 12, determine S12 stage of mean error: mean error refers to the mean value of all ultimate ranges of snake arms end joint segments and path joint segments, is used for weighing the average deviation size in tracing process; If mean error is then

$\stackrel{\&OverBar;}{e}=\frac{\underset{t=1}{\overset{nw}{\&Sigma;}}{d}_{\max t}}{nw}$

Step 13, determine S13 stage of control accuracy: control accuracy has referred to the distance of snake arms distal point and path ends point after path trace; Path produces according to paths planning method after the impact point detected by given needs, is namely the distance with impact point with the distance of path ends point; Control accuracy is used to weigh the order of accuarcy arriving impact point; This flow process so far terminates.