CN104401324A - Multi-objective optimization-based assisted parking system and multi-objective optimization-based assisted parking method - Google Patents

Abstract

The invention provides a multi-objective optimization-based assisted parking system, which comprises a vehicle speed sensor, an acceleration sensor, a multi-objective optimization controller, an assisted parking controller, a voice prompt device and a switch assembly; the vehicle speed sensor is arranged on a wheel; the acceleration sensor is arranged on a vehicle body; the vehicle speed sensor and the acceleration sensor are respectively connected with the multi-objective optimization controller; the multi-objective optimization controller, the assisted parking controller, the voice prompt device and the switch device are connected in sequence; the invention also provides a multi-objective optimization-based assisted parking method, which comprises the following steps: (1) establishing a multi-objective optimization control model; (2) designing a parameter constraint condition; (3) performing solving of a multi-objective planning control model by adopting a fgoalattain function in a MATLAB (matrix laboratory) optimization toolbox. The vehicle speed during a parking process is optimized, the time at the low-speed and high-fuel consumption stage of parking is shortened, the comfort of a driver during the parking process is improved, and the problem that the final vehicle attitude error of the parking is bigger is weakened.

Description

A kind of auxiliary parking system based on multiple-objection optimization and method

Technical field

The present invention relates to automatic parking technical field, be specifically related to a kind of auxiliary parking system based on multiple-objection optimization and method.

Background technology

As the important component part of driver assistance system, auxiliary parking system APS (Assisted Parking System) reduces chaufeur to park work capacity because having, alleviate the urban road traffic congestion brought because long-time road occupying is parked, reduce potential security risk in process of parking, obtain the extensive concern of each research institution and automobile vendor.Existing APS is many only for final body gesture design of parking, but, along with the universal gradually of APS and the increase of oil price, except necessary final body gesture of parking reaches except optimum, because the process of parking is in low vehicle speeds process, oil consumption is higher is the distinct disadvantage in this stage, and the deadline as far as possible controlling whole process of parking also becomes the important goal that APS pursues.In addition, for strengthening chaufeur to the degree of belief of APS, the acceleration/accel that the reduction stage of parking produces due to brake, travelling comfort is improved.This is the functional requirement of APS of new generation, and the basic characteristics of this function are, good final body gesture of parking, suitable the park speed of a motor vehicle and crew comfort.The key realizing APS of new generation is, proposes a kind of method based on multiple-objection optimization, namely considers final body gesture of parking, the speed of a motor vehicle of parking and chaufeur impression.At present, consider that the APS of simple target has had preliminary achievement both at home and abroad, but the method considering the multiple-objection optimization between three is seen in report not yet.

Summary of the invention

For solving the problems of the technologies described above, the invention provides a kind of auxiliary parking system based on multiple-objection optimization and method, make final body gesture of parking, park the speed of a motor vehicle and crew comfort etc. three the performance of aspect reach comprehensive optimum, the low speed of a motor vehicle and crew comfort and the Problems existing of parking cannot be taken into account in order to overcome traditional APS.

The invention provides a kind of auxiliary parking system based on multiple-objection optimization, comprise car speed sensor, acceleration pick-up, multiobjective optimal control device, auxiliary controller of parking, sound prompt device and switch assembly, described car speed sensor is arranged on wheel, described acceleration pick-up is arranged on vehicle body, described car speed sensor, acceleration pick-up is connected with described multiobjective optimal control device respectively, described multiobjective optimal control device, auxiliary controller of parking, sound prompt device, switch assembly connects successively, store in described multiobjective optimal control device and add up by test of many times final this spacing preceding object distance a obtained, final this spacing rear obstacle distance b, average displacement c and final this car left side edge line and the garage left border line angle theta of final this car left side edge relative parking stall left border line.When parking, open described switch assembly, described multiobjective optimal control device Real-time Collection car speed sensor obtains the speed of a motor vehicle v that parks real-time in process of parking, the chaufeur of vehicle-mounted acceleration pick-up collection produces acceleration/accel a when carrying out shut-down operation _y, and calculate the optimal value of each parameter, then pass to auxiliary controller of parking, the mode finally by voice message points out chaufeur to carry out parking manoeuvres.

The present invention also provides a kind of auxiliary method of parking based on multiple-objection optimization, comprises the following steps:

1) demand of final body gesture, suitable the park speed of a motor vehicle and crew comfort three aspects of parking according to auxiliary parking system, sets up the final body gesture objective function f that parks respectively ₁(x), the speed of a motor vehicle of parking objective function f ₂(x), crew comfort objective function f ₃(x);

2) according to the performance figure design parameters constraint condition based on the auxiliary parking system of multiple-objection optimization;

3) will to park final body gesture, park the speed of a motor vehicle and crew comfort etc. three the performance figure of aspect transform into single index, the fgoalattain function in MATLAB Optimization Toolbox is adopted to carry out solving of multiple objective programming Controlling model, finally determine based on final body gesture, the optimal value of the performance figure such as the speed of a motor vehicle and crew comfort of parking.

Further, using final this spacing preceding object distance a, finally this spacing rear obstacle distance b, finally this car left side edge relative to the weighted sum of the average displacement c of parking stall left border line and finally this car left side edge line and garage left border line angle theta as the final body gesture objective function f that parks ₁(x),

$f_1\left(x\right)=w_a\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{a}_i+w_b\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{b}_i+w_c\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{c}_i+w_{\mathrm{\θ}}\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\θ}}_i$

Wherein M represents the times of collection carrying out test of many times, w _afor a _iweight coefficient, w _bfor b _iweight coefficient, w _cfor c _iweight coefficient, w _θfor θ _iweight coefficient, obtain 50cm≤a≤95cm, 110cm≤b≤95cm ,-10cm≤c≤10cm according to test of many times data statistics ,-5 °≤θ≤5 °.

Further, using the weighted sum of real-time speed of a motor vehicle aviation value as the speed of a motor vehicle objective function f that parks ₂(x),

$f_2\left(x\right)=w_v\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{v}_i}{N}$

Wherein N represents the speed of a motor vehicle number that the stage Real-time Collection of parking arrives, w _vfor v _iweight coefficient, obtain according to car speed sensor the speed of a motor vehicle v that parks real-time in process that parks, and consider that actual conditions design the constraint condition 4km/h≤v≤8km/h of real-time speed of a motor vehicle aviation value.

Further, using the weighted sum of real-time vehicle longitudinal acceleration as crew comfort objective function f ₃(x),

$f_3\left(x\right)=w_{a_Y}\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{a}_{Y_i}$

Three parking manoeuvres can be produced in process of wherein parking, therefore carry out three cumulative tables of longitudinal direction of car acceleration/accel, for weight coefficient, gather chaufeur according to vehicle-mounted acceleration pick-up and produce acceleration/accel a when carrying out shut-down operation _y, design the bound of the longitudinal acceleration corresponding to comfort level ,-1m/s ²≤ a _y≤ 1m/s ².

Beneficial effect of the present invention: 1, by building multi-objective optimization question, solve final body gesture, the contradiction of parking between the speed of a motor vehicle and crew comfort.2, while final body gesture is well parked in maintenance, the speed of a motor vehicle of whole process of parking can be optimized, reduce the time in residing low speed height oil consumption stage of parking, improve the traveling comfort of chaufeur in the process of parking.3, the problem that final body gesture error of parking that is that cause is larger because the speed of a motor vehicle in the process of parking is too high is reduced.

Accompanying drawing explanation

Fig. 1 is the auxiliary parking system block diagram based on multiple-objection optimization;

Fig. 2 is the auxiliary concrete grammar diagram of circuit of parking based on multiple-objection optimization;

Fig. 3 is each parameter schematic diagram in final body gesture index of parking;

Fig. 4 is multiobjective optimal control device principle of work diagram of circuit.

Detailed description of the invention

Below in conjunction with accompanying drawing and specific embodiment, the present invention is further illustrated, but protection scope of the present invention is not limited to this.

As Fig. 1, shown in Fig. 3 and Fig. 4, a kind of auxiliary parking system based on multiple-objection optimization, comprise car speed sensor, acceleration pick-up, multiobjective optimal control device, auxiliary controller of parking, sound prompt device and switch assembly, described car speed sensor is arranged on wheel, described acceleration pick-up is arranged on vehicle body, described car speed sensor, acceleration pick-up is connected with described multiobjective optimal control device respectively, described multiobjective optimal control device, auxiliary controller of parking, sound prompt device, switch assembly connects successively, store in described multiobjective optimal control device and add up by test of many times final this spacing preceding object distance a obtained, final this spacing rear obstacle distance b, average displacement c and final this car left side edge line and the garage left border line angle theta of final this car left side edge relative parking stall left border line.When parking, open described switch assembly, described multiobjective optimal control device Real-time Collection car speed sensor obtains the speed of a motor vehicle v that parks real-time in process of parking, the chaufeur of vehicle-mounted acceleration pick-up collection produces acceleration/accel a when carrying out shut-down operation _y, and calculate the optimal value of each parameter, then pass to auxiliary controller of parking, the mode finally by voice message points out chaufeur to carry out parking manoeuvres.

As shown in Figure 2, a kind of auxiliary method of parking based on multiple-objection optimization, comprises the following steps:

1) to park final body gesture according to auxiliary parking system, the demand of suitable the park speed of a motor vehicle and crew comfort three aspects, to set up using final this spacing preceding object distance a, finally this spacing rear obstacle distance b, finally this car left side edge relative to the weighted sum of the average displacement c of parking stall left border line and finally this car left side edge line and garage left border line angle theta respectively as the final body gesture objective function f that parks ₁x (), using the weighted sum of real-time speed of a motor vehicle aviation value as the speed of a motor vehicle objective function f that parks ₂x (), using the weighted sum of real-time vehicle longitudinal acceleration as crew comfort objective function f ₃x (), Model for Multi-Objective Optimization, sets up multiobjective optimal control model.

2) according to the performance figure design parameters constraint condition based on the auxiliary parking system of multiple-objection optimization.

3) will to park final body gesture, park the speed of a motor vehicle and crew comfort etc. three the performance figure of aspect transform into single index, adopt the fgoalattain function in MATLAB Optimization Toolbox to carry out solving of multiple objective programming Controlling model.

In such scheme, using final this spacing preceding object distance a, finally this spacing rear obstacle distance b, finally this car left side edge relative to the weighted sum of the average displacement c of parking stall left border line and finally this car left side edge line and garage left border line angle theta as the final body gesture objective function f that parks ₁(x),

$f_1\left(x\right)=w_a\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{a}_i+w_b\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{b}_i+w_c\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{c}_i+w_{\mathrm{\θ}}\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\θ}}_i$

Wherein M represents the times of collection carrying out test of many times, w _afor a _iweight coefficient, w _bfor b _iweight coefficient, w _cfor c _iweight coefficient, w _θfor θ _iweight coefficient, obtain 50cm≤a≤95cm, 110cm≤b≤95cm ,-10cm≤c≤10cm according to test of many times data statistics ,-5 °≤θ≤5 °.

In such scheme, using the weighted sum of real-time speed of a motor vehicle aviation value as the speed of a motor vehicle objective function f that parks ₂(x),

$f_2\left(x\right)=w_v\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{v}_i}{N}$

Wherein N represents the speed of a motor vehicle number that the stage Real-time Collection of parking arrives, w _vfor v _iweight coefficient, specifically in implementation process, when the speed of a motor vehicle is too low, is easy to cause the phenomenon of parking and engine off, thus affects the continuity of reversing process.By testing, find that the minimum stabilizing speed of reverse gear of test vehicle is 4km/h on the spot.But when carrying out reversing experiment with 4km/h, the whole reversing process time is very short, occur that deviation is not easy adjustment.The chaufeur that technology is skilled again, be also adjust the speed of a motor vehicle in conjunction with power-transfer clutch and brake falling in the process in storehouse, the constraint condition therefore set is: 4km/h≤v≤8km/h.

In such scheme, using the weighted sum of real-time vehicle longitudinal acceleration as crew comfort objective function f ₃(x),

$f_3\left(x\right)=w_{a_Y}\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{a}_{Y_i}$

Three parking manoeuvres can be produced in process of wherein parking, therefore carry out three cumulative tables of longitudinal direction of car acceleration/accel, for weight coefficient, gather chaufeur according to vehicle-mounted acceleration pick-up and produce acceleration/accel a when carrying out shut-down operation _y, design the bound of the longitudinal acceleration corresponding to comfort level ,-1m/s ²≤ a _y≤ 1m/s ².

Described embodiment is the preferred embodiment of the present invention; but the present invention is not limited to above-mentioned embodiment; when not deviating from flesh and blood of the present invention, any apparent improvement that those skilled in the art can make, replacement or modification all belong to protection scope of the present invention.

Claims (5)

1. the auxiliary parking system based on multiple-objection optimization, it is characterized in that, comprise car speed sensor, acceleration pick-up, multiobjective optimal control device, auxiliary controller of parking, sound prompt device and switch assembly, described car speed sensor is arranged on wheel, described acceleration pick-up is arranged on vehicle body, described car speed sensor, acceleration pick-up is connected with described multiobjective optimal control device respectively, described multiobjective optimal control device, auxiliary controller of parking, sound prompt device, switch assembly connects described multiobjective optimal control device successively, auxiliary controller of parking, sound prompt device, switch assembly connects successively, store in described multiobjective optimal control device and add up by test of many times final this spacing preceding object distance a obtained, final this spacing rear obstacle distance b, average displacement c and final this car left side edge line and the garage left border line angle theta of final this car left side edge relative parking stall left border line,

When parking, open described switch assembly, described multiobjective optimal control device Real-time Collection car speed sensor obtains the speed of a motor vehicle v that parks real-time in process of parking, the chaufeur of vehicle-mounted acceleration pick-up collection produces acceleration/accel aY when carrying out shut-down operation, and calculate the optimal value of each parameter, pass to auxiliary controller of parking again, the mode finally by voice message points out chaufeur to carry out parking manoeuvres.

2., based on an auxiliary method of parking for multiple-objection optimization, it is characterized in that, comprise the following steps:

1) demand of final body gesture, suitable the park speed of a motor vehicle and crew comfort three aspects of parking according to auxiliary parking system, sets up the final body gesture objective function f that parks respectively ₁(x), the speed of a motor vehicle of parking objective function f ₂(x), crew comfort objective function f ₃(x);

2) according to the performance figure design parameters constraint condition based on the auxiliary parking system of multiple-objection optimization;

3) will to park final body gesture, park the speed of a motor vehicle and crew comfort etc. three the performance figure of aspect transform into single index, the fgoalattain function in MATLAB Optimization Toolbox is adopted to carry out solving of multiple objective programming Controlling model, finally determine based on final body gesture, the optimal value of the performance figure such as the speed of a motor vehicle and crew comfort of parking.

3. a kind of auxiliary method of parking based on multiple-objection optimization according to claim 2, it is characterized in that, using final this spacing preceding object distance a, finally this spacing rear obstacle distance b, finally this car left side edge relative to the weighted sum of the average displacement c of parking stall left border line and finally this car left side edge line and garage left border line angle theta as the final body gesture objective function f that parks ₁(x),

$f_1\left(x\right)=w_a\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{a}_i+w_b\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{b}_i+w_c\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{c}_i+w_{\mathrm{\θ}}\underset{i=1}{\overset{M}{\mathrm{\Σ}}}{\mathrm{\θ}}_i$

Wherein M represents the times of collection carrying out test of many times, w _afor a _iweight coefficient, w _bfor b _iweight coefficient, w _cfor c _iweight coefficient, w _θfor θ _iweight coefficient, obtain 50cm≤a≤95cm, 110cm≤b≤95cm ,-10cm≤c≤10cm according to test of many times data statistics ,-5 °≤θ≤5 °.

4. a kind of auxiliary method of parking based on multiple-objection optimization according to claim 2, is characterized in that, using the weighted sum of real-time speed of a motor vehicle aviation value as the speed of a motor vehicle objective function f that parks ₂(x),

$f_2\left(x\right)=w_v\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{v}_i}{N}$

Wherein N represents the speed of a motor vehicle number that the stage Real-time Collection of parking arrives, w _vfor v _iweight coefficient, obtain according to car speed sensor the speed of a motor vehicle v that parks real-time in process that parks, and consider that actual conditions design the constraint condition 4km/h≤v≤8km/h of real-time speed of a motor vehicle aviation value.

5. a kind of auxiliary method of parking based on multiple-objection optimization according to claim 2, is characterized in that, using the weighted sum of real-time vehicle longitudinal acceleration as crew comfort objective function f ₃(x),

$f_3\left(x\right)=w_{a_Y}\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{a}_{Y_i}$

Three parking manoeuvres can be produced in process of wherein parking, therefore carry out three cumulative tables of longitudinal direction of car acceleration/accel, for weight coefficient, gather chaufeur according to vehicle-mounted acceleration pick-up and produce acceleration/accel a when carrying out shut-down operation _y, design the bound of the longitudinal acceleration corresponding to comfort level ,-1m/s ²≤ a _y≤ 1m/s ².