CN105549589A - Foresight radar based collision avoidance method of unmanned ship - Google Patents

Abstract

The invention discloses a foresight radar based collision avoidance method of an unmanned ship. The unmanned ship, and a foresight radar, a pose sensor, a controller and an execution mechanism on the unmanned ship are included, the controller measures the orientation and distance of an obstacle according to data of the foresight radar and the pose sensor, the control quantity of the execution mechanism is adjusted via a collision avoidance control strategy, and the pose of the unmanned ship is adjusted to avoid the obstacle. According to the invention, image data of the foresight radar is introduced into the collision avoidance strategy of the unmanned ship, and the collision blind area of the unmanned ship is reduced. The collision avoidance strategy can resist complex barrier and echo interference, and the survival capability of the unmanned ship is improved.

Description

A kind of unmanned boat collision prevention method based on forward-looking radar

Technical field

The invention belongs to unmanned boat field of intelligent control technology, specifically, relate to a kind of unmanned boat collision prevention method based on forward-looking radar.

Background technology

Unmanned boat all has wide practical use in scientific research of seas, environmental monitoring, hydrologic survey and military affairs etc.Unmanned boat is operated in complicated marine environment, may there is unknown barrier as the ship that submerged reef, dykes and dams, navigation route cross, marine swim object, sea life etc., these failures that unmanned boat all may be caused to execute the task even threaten the safety of unmanned boat or other ships.

Forward-looking radar identifies the barrier in front by radioecho, but radar return comprises various clutter usually, Changes in weather than like rain, snow wait also cause a lot of interference to echo, so it is very difficult that unmanned boat hides obstacle by forward-looking radar; It is also difficult for when radar return finds multiple different target time, allow unmanned boat make keeping away barrier planning.

So, for technician, develop a kind of unmanned boat collision prevention method based on forward-looking radar, reasonable in design, the data of forward-looking radar and Position and attitude sensor record the azimuth-range of obstacle, and the pose of control device adjustment unmanned boat hides obstacle, avoid causing damage, make that unmanned boat is efficient in the water environment of more complicated, safety and complete traveling task fast, convenient and reliable, become problem demanding prompt solution.

Summary of the invention

The technical problem to be solved in the present invention overcomes above-mentioned defect, a kind of unmanned boat collision prevention method based on forward-looking radar is provided, reasonable in design, the data of forward-looking radar and Position and attitude sensor record the azimuth-range of obstacle, and the pose of control device adjustment unmanned boat hides obstacle, is effective unmanned boat automatic obstacle avoiding method, that improves unmanned boat under water keeps away barrier ability, avoid loss, make that unmanned boat is efficient in the water environment of more complicated, safety and complete traveling task fast, convenient and reliable.

The technical solution adopted in the present invention is:

Based on a unmanned boat collision prevention method for forward-looking radar, it is characterized in that: comprise unmanned boat, the forward-looking radar that unmanned boat is arranged, Position and attitude sensor, control device and topworks; Control device records the azimuth-range of obstacle according to the data of forward-looking radar and Position and attitude sensor, then by control of collision avoidance strategy, the controlled quentity controlled variable of adjustment topworks, and then the pose of adjustment unmanned boat hides obstacle.

Result according to forward-looking radar defines the orientation weight function and distance weight function that represent hazard level respectively to the azimuth-range of obstacle;

Orientation weight function is defined as:

$w_1=\mathrm{sgn}(x-c)e^{(-{(x-c)}^2)/\left({2\mathrm{\σ}}^2\right)}$

Function w ₁represent accurate Gaussian curve, sgn is sign function, and parameter x, c and σ are respectively position, central point and form parameter, and form parameter σ determines curve steepness;

Distance weight function is an asymmetrical polynomial curve, is defined as:

w ₂＝zmf(x,[a,b])

Function w ₂represent accurate Gaussian curve, a and b is the extreme value of curve sloping portion, determines the concavity of curve; Distance weight coefficient is defined as: being 1 when little 200 meters, is zero when being greater than 400 meters;

Last weights based on azimuth-range are by w ₁and w ₂product determine, the maximum knots modification in unmanned ship's head is 90 degree, and the knots modification in course is defined as:

ψ _oa(t,c)＝w ₁w ₂(π/4)

Wherein, t is time step, and c is evaluated barrier;

In single time step, the collision prevention course variable of all barriers is:

${\mathrm{\ψ}}_{oalook}\left(t\right)=\underset{1}{\overset{c}{\Σ}}{\mathrm{\ψ}}_{oa}(t,c).$

Unmanned boat is when keeping away barrier and running, and to be its formula related be for its speed and obstacle corner and hazard level:

ψ＝β+k _θθ

V＝k _vV _t

Wherein, β is the target course that global path planning obtains, and θ is that when running into barrier, unmanned boat is hide the fixed angle that obstacle turns, the course angle that ψ synthesizes for both the collision prevention angles calculated by target course and the avoidance algorithm of global path planning, k _θfor carrying out coefficient of angularity when course adjusts according to the Distance geometry angle of barrier and unmanned boat, V _tfor the target speed of a ship or plane of unmanned boat, k _vregulation coefficient several times during for running into barrier.

Owing to have employed technique scheme, compared with prior art, the present invention is reasonable in design, forward-looking radar view data is introduced in unmanned boat Robot dodge strategy, unmanned boat collision prevention blind area can be reduced, the data of forward-looking radar and Position and attitude sensor record the azimuth-range of obstacle, the pose of control device adjustment unmanned boat hides obstacle, that improves unmanned boat under water keeps away barrier ability, avoid loss, make that unmanned boat is efficient in the water environment of more complicated, safety and complete traveling task fast, convenient and reliable.

Below in conjunction with the drawings and specific embodiments, the invention will be further described simultaneously.

Accompanying drawing explanation

Fig. 1 is the principle of work block diagram of an embodiment of the present invention;

Embodiment

Embodiment:

As shown in Figure 1, a kind of unmanned boat collision prevention method based on forward-looking radar, is characterized in that: comprise unmanned boat, the forward-looking radar that unmanned boat is arranged, Position and attitude sensor, control device and topworks; Control device records the azimuth-range of obstacle according to the data of forward-looking radar and Position and attitude sensor, then by control of collision avoidance strategy, the controlled quentity controlled variable of adjustment topworks, and then the pose of adjustment unmanned boat hides obstacle.

It is that sound spectrogram data pass to control device that forward-looking radar records.Generally, control device is computer for controlling.Position and the attitude of what Position and attitude sensor recorded is unmanned boat.Computer for controlling to adjust avoiding barrier to topworks according to the position of sound spectrogram data and unmanned boat and attitude.

Result according to forward-looking radar defines the orientation weight function and distance weight function that represent hazard level respectively to the azimuth-range of obstacle;

Orientation weight function is defined as:

$w_1=\mathrm{sgn}(x-c)e^{(-{(x-c)}^2)/\left({2\mathrm{\σ}}^2\right)}$

Function w ₁represent accurate Gaussian curve, sgn is sign function, and parameter x, c and σ are respectively position, central point and form parameter, and form parameter σ determines curve steepness.

Distance weight function is an asymmetrical polynomial curve, is defined as:

w ₂＝zmf(x,[a,b])

Function w ₂represent accurate Gaussian curve, a and b is the extreme value of curve sloping portion, determines the concavity of curve; Distance weight coefficient is defined as: being 1 when little 200 meters, is zero when being greater than 400 meters.

Last weights based on azimuth-range are by w ₁and w ₂product determine, the maximum knots modification in unmanned ship's head is 90 degree, and the knots modification in course is defined as:

ψ _oa(t,c)＝w ₁w ₂(π/4)

Wherein, t is time step, and c is evaluated barrier.

In single time step, the collision prevention course variable of all barriers is:

${\mathrm{\ψ}}_{oalook}\left(t\right)=\underset{1}{\overset{c}{\Σ}}{\mathrm{\ψ}}_{oa}(t,c).$

Unmanned boat is when keeping away barrier and running, and to be its formula related be for its speed and obstacle corner and hazard level:

ψ＝β+k _θθ

V＝k _vV _t

Wherein, β is the target course that global path planning obtains, and θ is that when running into barrier, unmanned boat is hide the fixed angle that obstacle turns, the course angle that ψ synthesizes for both the collision prevention angles calculated by target course and the avoidance algorithm of global path planning, k _θfor carrying out coefficient of angularity when course adjusts according to the Distance geometry angle of barrier and unmanned boat, the angle turned when namely hazard level is large is large, and the angle that hazard level hour turns is little.V _tfor the target speed of a ship or plane of robot, k _vregulation coefficient several times during for running into barrier, namely the amplitude that reduces of the large hourly velocity of hazard level is large, and the amplitude that the little hourly velocity of hazard level reduces is little.

Forward-looking radar view data is introduced in unmanned boat Robot dodge strategy by the present invention, can reduce unmanned boat collision prevention blind area.The collision prevention strategy of the present invention's design can tackle complicated obstacle and echo interference, improves the viability of unmanned boat.

The present invention is not limited to above-mentioned preferred implementation, and anyone should learn the structure change made under enlightenment of the present invention, and every have identical or akin technical scheme with the present invention, all belongs to protection scope of the present invention.

Claims (3)

1., based on a unmanned boat collision prevention method for forward-looking radar, it is characterized in that: comprise unmanned boat, the forward-looking radar that unmanned boat is arranged, Position and attitude sensor, control device and topworks; Control device records the azimuth-range of obstacle according to the data of forward-looking radar and Position and attitude sensor, then by control of collision avoidance strategy, the controlled quentity controlled variable of adjustment topworks, and then the pose of adjustment unmanned boat hides obstacle.

2. the unmanned boat collision prevention method based on forward-looking radar according to claim 1, is characterized in that: the result according to forward-looking radar defines the orientation weight function and distance weight function that represent hazard level respectively to the azimuth-range of obstacle;

Orientation weight function is defined as:

$w_1=sgn(x-c)e^{(-{\left(x-c\right)}^2)/\left(2{\mathrm{\σ}}^2\right)}$

Function w ₁represent accurate Gaussian curve, sgn is sign function, and parameter x, c and σ are respectively position, central point and form parameter, and form parameter σ determines curve steepness;

Distance weight function is an asymmetrical polynomial curve, is defined as:

w ₂＝zmf(x,[a,b])

Function w ₂represent accurate Gaussian curve, a and b is the extreme value of curve sloping portion, determines the concavity of curve; Distance weight coefficient is defined as: being 1 when little 200 meters, is zero when being greater than 400 meters;

Last weights based on azimuth-range are by w ₁and w ₂product determine, the maximum knots modification in unmanned ship's head is 90 degree, and the knots modification in course is defined as:

ψ _oa(t,c)＝w ₁w ₂(π/4)

Wherein, t is time step, and c is evaluated barrier;

In single time step, the collision prevention course variable of all barriers is:

${\mathrm{\ψ}}_{oalook}\left(t\right)=\underset{1}{\overset{c}{\Σ}}{\mathrm{\ψ}}_{oa}(t,c).$

3. the unmanned boat collision prevention method based on forward-looking radar according to claim 2, is characterized in that:

Unmanned boat is when keeping away barrier and running, and to be its formula related be for its speed and obstacle corner and hazard level:

ψ＝β+k _θθ

V＝k _vV _t

Wherein, β is the target course that global path planning obtains, and θ is that when running into barrier, unmanned boat is hide the fixed angle that obstacle turns, the course angle that ψ synthesizes for both the collision prevention angles calculated by target course and the avoidance algorithm of global path planning, k _θfor carrying out coefficient of angularity when course adjusts according to the Distance geometry angle of barrier and unmanned boat, V _tfor the target speed of a ship or plane of unmanned boat, k _vregulation coefficient several times during for running into barrier.