CN103354030B - Method for determining road traffic situation by utilizing floating bus CAN bus information - Google Patents

Abstract

The invention, which belongs to the field of road traffic situation determination method, relates to a method for determining a road traffic situation by utilizing floating bus CAN bus information. A piece of vehicle body CAN bus information is used for accurately calculating a driving uniform velocity of a floating car on the road and partial invalid information in the vehicle velocity information is rejected, thereby effectively obtaining road traffic information. The advantages of the method are as follows: the method is not no longer dependent on an accurate degree of satellite navigation positioning; and vehicle velocity information can still be obtained under the circumstances that satellite signal receiving is influenced by a severe weather condition or a city building. On the basis of analyzing of vehicle body CAN bus data, invalid velocity value in the passenger on-off time period of the bus can be rejected accurately during the post-calculation process, thereby providing the guarantee for effectiveness of uniform velocity calculation and further ensuring real-time and accurate performances.

Description

Bus CAN information of floating is utilized to differentiate the method for road traffic condition

Technical field

The present invention relates to and adopt bus as floating vehicle, utilize the information of vehicle body CAN to differentiate the method for road traffic condition.

Background technology

Urban transportation is urban society's activity, the tie of economic activity and soul, and " quick, convenient, comfortable, efficient Traffic Systems is to urban economy development, and Living consumption improves, and city low consumption environmental protection construction serves extremely crucial effect; Otherwise the urban transportation of blocking up wastes the travel time of resident, adds Trip Costs, reduce the work efficiency of resident, cause unnecessary energy resource consumption, traffic jam is also the key factor causing traffic hazard to take place frequently in addition.

The conventional approach of transport solution problem builds the traffic infrastructure such as road, overpass, but the geographical space in city is extremely limited, the construction speed of traffic infrastructure, well below motor vehicle growth rate, only relies on increase means of transportation cannot improve current traffic completely.Under the traffic programme prerequisite of science, increase road equipment be only the key of improvement traffic problems with basic in conjunction with the traffic technique raising road passage capability of modern science simultaneously.The developed countries such as America and Europe have developed much new technology in intelligent transportation system (ITS) research, and carry out the intelligentized demonstration of Road Transportation in each big and medium-sized cities.And the most important detection no more than transport information in intelligent transportation system.For how to obtain Traffic Information accurately, employ in a large number in city traditionally as the equipment such as coil checker, microwave detector and radar detector detect the information such as the magnitude of traffic flow on each main roads, but, these fixing checkout equipments have born defect, they can only obtain the telecommunication flow information of neighbouring a period of time mostly, also be attached with high installation and maintenance expense in addition, therefore, the method using fixing checkout equipment to obtain transport information does not use.

Therefore, " Floating Car " is suggested as a new concept.In recent years, international intelligent transportation system it can be used as one of important means obtaining Traffic Information.Its basic functional principle is, the Floating Car being equipped with gps system under steam the cycle reception and record the longitude and latitude of vehicle, height above sea level, the information such as direction and instantaneous velocity, via wireless communication networks, information control center passes through periodically and carries out information interaction between vehicle termination and can collect relevant information, then information control center is through map match, the data handling procedures such as path analysis, thus calculate the relevant space time information of GPS vehicle termination in city road network, obtain this Floating Car through the Vehicle Speed of road and traffic congestion information.The extensive employing of floating car technology considerably reduces data acquisition expense on the one hand, contributes to the generation of direct economy interests; On the other hand, the widespread use of this system is that the management and reform of urban traffic conditions provides Information Assurance, effectively can alleviate the present situation of current big and medium-sized cities traffic congestion, promote traffic system travelling speed further, bring positive social influence.

Due to the impact by the factor such as manpower, fund, each metropolitan vehicle supervision department of China can not have a large amount of special Floating Car to go to gather telecommunication flow information.From economic considerations, utilize the urban road traffic vehicles being provided with GPS, comprise private car, public transit vehicle, electric car, taxi, lorry etc., replace special Floating Car to gather road traffic stream information, the problem of special Floating Car lazy weight can be made up to a certain extent.

The bus that satellite navigation is housed is used to have following advantage as Floating Car: first, public bus network is numerous, has larger area coverage in city, high to road network coverage rate; Secondly, bus, according to line operation, has fixing website, and driving order of classes or grades at school performs according to operation plan; Again, public transit vehicle, relative to other public vehicles, is not only under the jurisdiction of some enterprises, and vehicle is managed concentratedly, keeped in repair and deposit; Finally, bus is as the main oversize vehicle of urban road traffic flow, traffic flow is subject to the impact of bus to a great extent, or can say a pith of bus inherently traffic flow, therefore in the application example of a lot of Floating Car, all uses bus its carrier the most.

The current various method utilizing Floating Car to obtain Traffic Information is all depend on gps system substantially, calculating the road average velocity of vehicle process, it is all the locating information using GPS, then utilizing as multiple regression, fuzzy reasoning, the model such as rate integrating and curve calculates general average velocity, the computing method of this speed are too strong for the dependence of positioning precision and other external condition, and the result calculated also is inaccurate obtaining, in addition, in big city, building stand in great numbers, satellite-signal cannot be received often, this more exacerbates the instability of GPS scheme.Summary of the invention

The invention provides a kind of method utilizing floating bus CAN information to differentiate road traffic condition, object is to provide a kind of vehicle body CAN information that uses and accurately calculates the traveling average rate of Floating Car on road, thus effectively obtains Traffic Information.

The technical scheme that the present invention takes comprises the following steps:

(1) different travel routes information is read according to the difference of bus routes, i.e. PATH file, initialization terminates to carry out path adaptation according to vehicle operating track and bus vehicle line afterwards, vehicle location is to a certain road the most at last, map match terminates rear toggle speed and calculates timer T, and this timer is used to calculate effective running time;

(2) receive the data message of fault CAN and be saved in file ERROR by the failure message obtained according to fault diagnosis protocol analysis, described failure message comprises the timestamp of fault type and the generation of fault message; The velocity information obtained according to the parsing of information CAN agreement is also saved in file SPEED by the data message of reception information CAN; Receive the data message of vehicle body CAN and be saved in file CMD by resolving according to vehicle body CAN protocol the vehicle body command information obtained;

(3) judge that whether current driving speed is as 0, if not, continue to receive CAN data, otherwise use three files in step (two) and invalid data to reject algorithm by 0 invalid speed data rejecting;

(4) path travelled according to bus differentiates whether vehicle enters a new section, if arrive new section, average velocity computing method are so used to calculate the actual travel average rate V of a road, calculate in rear removing SPEED file, ERROR file and CMD file and had the information of shutting bar road, finally the identify label ID of a upper road and bus have been travelled average rate V and be sent to center by wireless network; If bus also travels on original path, these average velocity computing method are so also used to travel average rate v to the stage calculating this road _αwith travel the number percent θ of distance, last bus again by wireless network by road identify label ID, stage average rate v _αcenter is sent to traveling distance number percent θ.

The step that invalid data described in step of the present invention (three) rejects algorithm is;

(1) first judge whether occur speed data be zero, i.e. v _t==0, if forward to (2), otherwise forward to (9);

(2) now process zero data, judge whether, when timestamp is t, catastrophic failure occurs according to fault file ERROR, if not forwarding to (3), otherwise illustrate and directly reject this data, forward to (6);

(3) now illustrate catastrophic failure does not occur, then judge whether according to the command file CMD of vehicle body CAN the action that door contact interrupter occurs when timestamp is t, i.e. DOOR_OPEN==1, if forwarded to (4), otherwise forwards to (12);

(4) action of current generation car door opening is now described, so check whether car door opening mark DOOR_OPEN==1, if had, illustrate that this action is that closed door, i.e. bus complete on-board and off-board process, otherwise illustrate it is open car door, namely start on-board and off-board; The former forwards to (5), and the latter forwards to (13);

(5) car door opening mark is first cancelled, i.e. DOOR_OPEN=0, owing to now there is the action of closed door, therefore the on-board and off-board process of bus terminates, next be that bus accelerates to sail out of stop website, in order to the error that the moderating process be equilibrated at when bus enters the station causes in overall calculation process, therefore here arrange and reject delay mark DEL_MAK=1, this label table is shown in a period of time after this and effective for part speed data can be continued to reject, and forwards to (6);

(6) this has walked the action of rejecting speed data, namely performs SPEED->delete (v _t), forward to (7);

(7) judge whether total data process to complete, if forwarding to (8), otherwise by time t from adding 1, then forwarding (1) to and starting next circulation;

(8) reject algorithm to terminate;

(9) now process non-zero, check whether to exist and reject delay designations DEL_MAK==1, if had, illustrate and now still data should be rejected, forward to (10), otherwise forward to (6);

(10) current speed v is checked _twhether reach threshold speed v _βif do not reached, should continue to reject, forward to (6), otherwise explanation completes whole rejecting processes, so forwards to (11);

(11) this step cancels rejecting delay designations DEL_MAK=0, represents the end of rejecting process, forwards to (6);

(12) now checked whether car door opening mark DOOE_OPEN==1, if had, then illustrated and be in now in bus on-board and off-board process, forward to (6), otherwise forward to (9);

(13) now illustrate that bus just stops at stop website and opens car door, therefore car door opening mark DOOE_OPEN=1 should be set, forward to (6);

Average velocity computing method described in step of the present invention (four) comprise the following steps;

After the invalid speed data of use rejects algorithm process, the speed data in SPEED file just can be used for calculating average velocity; The mode of operating speed integration carrys out accurate Calculation distance travelled, then in the cumulative sum divided by the time, finally draws the average velocity of traveling;

Calculate bus operating range SUM and be initialized as 0, the SUM that has no progeny in speed timer T generation is each time from adding the new stretch journey produced, and publicity is as shown in (I):

$\mathrm{SUM}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j=1}{\overset{m-1}{\mathrm{\Σ}}}\mathrm{\Δt}(v_j^i+v_{j+1}^i)/2---\left(I\right)$

Speed data in speed file SPEED is the approximately continuous rate curve increased progressively for the time interval with Δ t on timestamp, but after being through the calculating of invalid speed data rejecting algorithm, approximately continuous rate curve can be cut into n the sub-curve of approximately continuous speed, and the outer cumulative sum that therefore SUM calculates is the calculated value of the sub-curve of cumulative single speed; For the sub-curve of each speed, due to continuous print two velocity amplitudes timestamp between difference be fixing, i.e. Δ t, therefore, the method of infinitesimal analysis is used to calculate this section of distance, wherein i represents it is i-th sub-curve of speed, and j represents a jth speed data in the sub-curve of speed, and m is the number of speed data;

Calculating public transport becomes running time TIME to be initialized as 0, and at the TIME that has no progeny in speed timer T generation each time from adding the new one period of effective time produced, publicity is as shown in (II);

$\mathrm{TIME}=\underset{\mathrm{\σ}=1}{\overset{k}{\mathrm{\Σ}}}\mathrm{\Δt}(n_t^{\mathrm{\σ}}-n_d^{\mathrm{\σ}})---\left(\mathrm{II}\right)$

The calculating of time is also separated by speed timer T, has k speed timer interruption in driving process, be exactly the time therefore during the outer cumulative sum each timer timing that calculates of TIME, during each timing, total mistake there will be ^σn _tindividual speed data, and have after the invalid speed data of use rejects algorithm calculating ^σn _dindividual speed data is deleted, and therefore effective time is Δ t( ^σn _t- ^σn _d);

After drawing SUM and TIME, the computing formula of average velocity AVG_SPEED is as shown in (III):

$\mathrm{AVG}\_\mathrm{SPEED}=\frac{\mathrm{SUM}}{\mathrm{TIME}}---\left(\mathrm{III}\right).$

Advantage of the present invention is: the order of accuarcy being 1. no longer dependent on satellite navigation location, still can obtain vehicle speed information when weather condition is severe or city building affect satellite signal receiving; 2. the velocity information utilizing vehicle body CAN to obtain is almost continuous print, because just having speed message every 100ms is distributed in CAN network, velocity distribution curve complete on road can be obtained completely like this, instead of velocity amplitude on original road relying on the uncertain anchor point of satnav generation to calculate, this is more accurate and stable beyond doubt; 3. according to the analysis to vehicle body CAN data, accurately can show whether floating bus is on-board and off-board of arriving at a station normally, so that the invalid velocity amplitude in the removal bus on-board and off-board period errorless when the later stage calculates, this validity calculated for average rate has provided a guarantee; 4. the fault that vehicle occurs can be detected according to the analysis of fault CAN data, thus reject the velocity sag because vehicle trouble causes when the process of car speed zero data.These advantages are in the past not available for floating vehicle system, by the utilization to bottom CAN, make Floating Car be tending towards accurate for the perception of road traffic condition.5. the present invention not only has the upper section to vehicle runs over to carry out off-line differentiation when calculating vehicle and travelling average rate, and more differentiate condition of road surface when locating each time and upgrade, real-time and accuracy are guaranteed further.

Accompanying drawing explanation

Fig. 1 is process flow diagram of the present invention;

Fig. 2 is the process flow diagram of the rejecting algorithm of invalid data of the present invention;

Fig. 3 is the simulation experiment result figure of the present invention.

Embodiment

Comprise the following steps:

(1) different travel routes information is read according to the difference of bus routes, i.e. PATH file, initialization terminates to carry out path adaptation according to vehicle operating track and bus vehicle line afterwards, vehicle location is to a certain road the most at last, map match terminates rear toggle speed and calculates timer T, and this timer is used to calculate effective running time;

(2) receive the data message of fault CAN and be saved in file ERROR by the failure message obtained according to fault diagnosis protocol analysis, described failure message comprises the timestamp of fault type and the generation of fault message; The velocity information obtained according to the parsing of information CAN agreement is also saved in file SPEED by the data message of reception information CAN; Receive the data message of vehicle body CAN and be saved in file CMD by resolving according to vehicle body CAN protocol the vehicle body command information obtained;

(3) judge that whether current driving speed is as 0, if not, continue to receive CAN data, otherwise use three files in step (two) and invalid data to reject algorithm by 0 invalid speed data rejecting;

(4) path travelled according to bus differentiates whether vehicle enters a new section, if arrive new section, average velocity computing method are so used to calculate the actual travel average rate V of a road, calculate in rear removing SPEED file, ERROR file and CMD file and had the information of shutting bar road, finally the identify label ID of a upper road and bus have been travelled average rate V and be sent to center by wireless network; If bus also travels on original path, these average velocity computing method are so also used to travel average rate v to the stage calculating this road _αwith travel the number percent θ of distance, last bus again by wireless network by road identify label ID, stage average rate v _αcenter is sent to traveling distance number percent θ.

The step that invalid data described in step of the present invention (three) rejects algorithm is;

(1) first judge whether occur speed data be zero, i.e. v _t==0, if forward to (2), otherwise forward to (9);

(2) now process zero data, judge whether, when timestamp is t, catastrophic failure occurs according to fault file ERROR, if not forwarding to (3), otherwise illustrate and directly reject this data, forward to (6);

(3) now illustrate catastrophic failure does not occur, then judge whether according to the command file CMD of vehicle body CAN the action that door contact interrupter occurs when timestamp is t, i.e. DOOR_OPEN==1, if forwarded to (4), otherwise forwards to (12);

(4) action of current generation car door opening is now described, so check whether car door opening mark DOOR_OPEN==1, if had, illustrate that this action is that closed door, i.e. bus complete on-board and off-board process, otherwise illustrate it is open car door, namely start on-board and off-board; The former forwards to (5), and the latter forwards to (13);

(5) car door opening mark is first cancelled, i.e. DOOR_OPEN=0, owing to now there is the action of closed door, therefore the on-board and off-board process of bus terminates, next be that bus accelerates to sail out of stop website, in order to the error that the moderating process be equilibrated at when bus enters the station causes in overall calculation process, therefore here arrange and reject delay mark DEL_MAK=1, this label table is shown in a period of time after this and effective for part speed data can be continued to reject, and forwards to (6);

(6) this has walked the action of rejecting speed data, namely performs SPEED->delete (v _t), forward to (7);

(7) judge whether total data process to complete, if forwarding to (8), otherwise by time t from adding 1, then forwarding (1) to and starting next circulation;

(8) reject algorithm to terminate;

(9) now process non-zero, check whether to exist and reject delay designations DEL_MAK==1, if had, illustrate and now still data should be rejected, forward to (10), otherwise forward to (6);

(10) current speed v is checked _twhether reach threshold speed v _βif do not reached, should continue to reject, forward to (6), otherwise explanation completes whole rejecting processes, so forwards to (11);

(11) this step cancels rejecting delay designations DEL_MAK=0, represents the end of rejecting process, forwards to (6);

(12) now checked whether car door opening mark DOOE_OPEN==1, if had, then illustrated and be in now in bus on-board and off-board process, forward to (6), otherwise forward to (9);

(13) now illustrate that bus just stops at stop website and opens car door, therefore car door opening mark DOOE_OPEN=1 should be set, forward to (6);

Average velocity computing method described in step of the present invention (four) comprise the following steps;

After the invalid speed data of use rejects algorithm process, the speed data in SPEED file just can be used for calculating average velocity; The mode of operating speed integration carrys out accurate Calculation distance travelled, then in the cumulative sum divided by the time, finally draws the average velocity of traveling;

Calculate bus operating range SUM and be initialized as 0, the SUM that has no progeny in speed timer T generation is each time from adding the new stretch journey produced, and publicity is as shown in (I):

$\mathrm{SUM}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j=1}{\overset{m-1}{\mathrm{\Σ}}}\mathrm{\Δt}(v_j^i+v_{j+1}^i)/2---\left(I\right)$

Speed data in speed file SPEED is the approximately continuous rate curve increased progressively for the time interval with Δ t on timestamp, but after being through the calculating of invalid speed data rejecting algorithm, approximately continuous rate curve can be cut into n the sub-curve of approximately continuous speed, and the outer cumulative sum that therefore SUM calculates is the calculated value of the sub-curve of cumulative single speed; For the sub-curve of each speed, due to continuous print two velocity amplitudes timestamp between difference be fixing, i.e. Δ t, therefore, the method of infinitesimal analysis is used to calculate this section of distance, wherein i represents it is i-th sub-curve of speed, and j represents a jth speed data in the sub-curve of speed, and m is the number of speed data;

Calculating public transport becomes running time TIME to be initialized as 0, and at the TIME that has no progeny in speed timer T generation each time from adding the new one period of effective time produced, publicity is as shown in (II);

$\mathrm{TIME}=\underset{\mathrm{\σ}=1}{\overset{k}{\mathrm{\Σ}}}\mathrm{\Δt}(n_t^{\mathrm{\σ}}-n_d^{\mathrm{\σ}})---\left(\mathrm{II}\right)$

The calculating of time is also separated by speed timer T, has k speed timer interruption in driving process, be exactly the time therefore during the outer cumulative sum each timer timing that calculates of TIME, during each timing, total mistake there will be ^σn _tindividual speed data, and have after the invalid speed data of use rejects algorithm calculating ^σn _dindividual speed data is deleted, and therefore effective time is Δ t( ^σn _t- ^σn _d);

After drawing SUM and TIME, the computing formula of average velocity AVG_SPEED is as shown in (III):

$\mathrm{AVG}\_\mathrm{SPEED}=\frac{\mathrm{SUM}}{\mathrm{TIME}}---\left(\mathrm{III}\right).$

In general the working line of bus is fixing, and we need the public bus network determined in advance and bus locating information and electronic chart to combine to judge current the exercised road information of bus, comprise the position relationship with bus station.Whether the map match of vehicle accurately can depend on the precision of satellite navigation location, and because satellite navigation exists drift phenomenon, therefore the judgement of the travel route of vehicle can not simply to use between vehicle location point to each paths most short lines to decide.Because the present invention uses bus as Floating Car entity, according to the feature that jack per station bus travels on respective fixed course, first mode of the present invention adopts this bus travel route file of typing PATH, bus is navigated to a certain section on its regulation travel route by the track that bus consecutive tracking dot information then can be used to be formed, complete judgement and the map match of travel route, complete bus travel route to judge, after navigating to a certain section by bus, the attribute information in this section can be obtained, as section end points longitude and latitude, the information such as speed-limiting messages and road section ID, these information will travel in average rate at calculating bus and be used.

The rejecting of the inactive portion of vehicle speed information comprises: bus enters the station the abnormal speed information etc. that the invalid velocity information in on-board and off-board stage, vehicle trouble cause.Whether bus is entered the station to be compared with vehicle self poisoning by the longitude and latitude of Localization of railway station point and learns, and have the behavior of on-board and off-board whether can have the behavior of switch by learning the reading of vehicle body CAN data car door; The abnormal speed data that vehicle trouble is can by determining the analysis of fault CAN data.Invalid zero data not only will be rejected by this one-phase, also will reject the vehicle speed information of relevant range, as the deceleration/accelerator before and after on-board and off-board.

The traveling average rate that Floating Car calculates on road is the essential condition judging whether road blocks up.The present invention uses the velocity information in vehicle body CAN, therefore can form continuous print rate curve on road, after the rejecting by the invalid velocity information of Part II, carries out integration just can calculate this road average rate accurately to this rate curve.

In the analytical approach of the floating bus road traffic condition based on CAN information, the rejecting of invalid velocity information is a step important in the present invention.The invalid velocity information of bus is rejected and can be divided into two classes: the first kind, sails website into and again accelerate, in the process of setting out on a journey, can obtain similar U-shaped rate curve in high-speed CAN bus after on-board and off-board at bus.But when considering that on road, vehicle travels average rate, this segment data is should be not calculated, therefore, this in rate curve section U-shaped data are rejected at the generation time according to the car door opening message that low speed CAN is issued by the present invention, and this includes the moderating process of bus before sailing website into, bus accelerates the data of sailing out of in the process of website at the docking process of website and bus.In actual mechanical process, the last period of this section of U-shaped data that should be disallowable, namely bus enters the station deceleration part, be difficult in calculating in real time processed, so the boost phase the present invention of sailing out of website at bus has inquired into suitable method eliminate a part of data to balance the deviation of the first half of U-shaped data more.Equations of The Second Kind, in bus driving process, the various fault of unavoidable appearance, and degree of accuracy of the present invention depends on accuracy and the real-time of data in high-speed CAN bus, therefore, the failure message in operational failure CAN of the present invention screens the accuracy of velocity information in high-speed CAN bus.When fault CAN occurring some affects the fault message of speed, the velocity information in the corresponding failure time period rejected in processing procedure, and record this section of blank time, this is in order to more accurate when calculating average velocity.

Beneficial effect of the present invention is further illustrated below by emulation experiment.

This emulation experiment adopts the high-speed CAN bus information of true car, acquires the velocity information of bus at two sections of adjacent segments of Forward Avenue, Changchun.The result of emulation experiment as shown in Figure 3.Real-time speed curve is the velocity information of bus, and the time span of the velocity information that this emulation experiment gathers was from 0 second to 229.73 seconds, and the traveling that bus is complete two sections of adjacent segments, the joint of two sections of roads occurred near 121.09 seconds.Figure intermediate cam symbol represents door contact interrupter message has appearred in low speed CAN, before 34.22 seconds, 35 kilometers/and point that place per hour occurs represents the catastrophic failure message affecting appearring in fault CAN velocity information.

What real vehicle was simulated is the driving cycle on two sections of roads, first paragraph road occurs one is stopped website and two place's congestion points, second segment road occurs two are stopped websites and zero congestion points.The method proposed in traditional GPS computing method and the present invention is adopted respectively in emulation.In Fig. 3, the point of the average velocity that traditional location algorithm calculates represents the bus mean velocity information of the interruption calculated in GPS method, and the point of the average velocity that the method that this experiment proposes calculates represents the bus average velocity calculated in the inventive method.

Table 1 emulation experiment contrast table

Shown in Fig. 3 and table 1, in first section, the result that GPS method calculates slightly is worse than the result that the inventive method calculates, and in second section, the result that the inventive method realizes obviously is better than the value that traditional GPS method calculates.This shows that the differentiation of the city bus road traffic condition using the inventive method is more rationally with accurate.

Claims (3)

1. utilize bus CAN information of floating to differentiate a method for road traffic condition, it is characterized in that comprising the following steps:

(1) different travel routes information is read according to the difference of bus routes, i.e. PATH file, initialization terminates to carry out path adaptation according to vehicle operating track and bus vehicle line afterwards, vehicle location is to a certain road the most at last, map match terminates rear toggle speed and calculates timer T, and this timer is used to calculate effective running time;

(2) receive the data message of fault CAN and be saved in file ERROR by the failure message obtained according to fault diagnosis protocol analysis, described failure message comprises the timestamp of fault type and the generation of fault message; The velocity information obtained according to the parsing of information CAN agreement is also saved in file SPEED by the data message of reception information CAN; Receive the data message of vehicle body CAN and be saved in file CMD by resolving according to vehicle body CAN protocol the vehicle body command information obtained;

(3) judge that whether current driving speed is as 0, if not, continue to receive CAN data, otherwise use three files in step (two) and invalid data to reject algorithm by 0 invalid speed data rejecting;

(4) path travelled according to bus differentiates whether vehicle enters a new section, if arrive new section, average velocity computing method are so used to calculate the actual travel average rate V of a road, calculate in rear removing SPEED file, ERROR file and CMD file and had the information of shutting bar road, finally the identify label ID of a upper road and bus have been travelled average rate V and be sent to center by wireless network; If bus also travels on original path, these average velocity computing method are so also used to travel average rate v to the stage calculating this road _αwith travel the number percent θ of distance, last bus again by wireless network by road identify label ID, the stage travels average rate v _αcenter is sent to traveling distance number percent θ.

2. utilization according to claim 1 bus CAN information of floating differentiates the method for road traffic condition, and the step that the invalid data that it is characterized in that described in step (three) rejects algorithm is;

(1) first judge whether occur speed data be zero, i.e. v _t==0, if forward to (2), otherwise forward to (9);

(2) now process zero data, judge whether, when timestamp is t, catastrophic failure occurs according to fault file ERROR, if not forwarding to (3), otherwise illustrate and directly reject this data, forward to (6);

(3) now illustrate catastrophic failure does not occur, then judge whether according to the command file CMD of vehicle body CAN the action that door contact interrupter occurs when timestamp is t, i.e. DOOR_OPEN==1, if forwarded to (4), otherwise forwards to (12);

(4) action of current generation car door opening is now described, so check whether car door opening mark DOOR_OPEN==1, if had, illustrate that this action is that closed door, i.e. bus complete on-board and off-board process, otherwise illustrate it is open car door, namely start on-board and off-board; The former forwards to (5), and the latter forwards to (13);

(5) car door opening mark is first cancelled, i.e. DOOR_OPEN=0, owing to now there is the action of closed door, therefore the on-board and off-board process of bus terminates, next be that bus accelerates to sail out of stop website, in order to the error that the moderating process be equilibrated at when bus enters the station causes in overall calculation process, therefore here arrange to reject and postpone mark DEL_MAK=1, this label table is shown in a period of time after this and effective for part speed data can be continued to reject, and forwards to (6);

(6) this has walked the action of rejecting speed data, namely performs SPEED->delete (v _t), forward to (7);

(7) judge whether total data process to complete, if forwarding to (8), otherwise by time t from adding 1, then forwarding (1) to and starting next circulation;

(8) reject algorithm to terminate;

(9) now process non-zero, check whether to exist and reject delay designations DEL_MAK==1, if had, illustrate and now still data should be rejected, forward to (10), otherwise forward to (6);

(10) current speed v is checked _twhether reach threshold speed v _βif do not reached, should continue to reject, forward to (6), otherwise explanation completes whole rejecting processes, so forwards to (11);

(11) this step cancels rejecting delay designations DEL_MAK=0, represents the end of rejecting process, forwards to (6);

(12) now checked whether car door opening mark DOOE_OPEN==1, if had, then illustrated and be in now in bus on-board and off-board process, forward to (6), otherwise forward to (9);

(13) now illustrate that bus just stops at stop website and opens car door, therefore car door opening mark DOOE_OPEN=1 should be set, forward to (6).

3. utilization according to claim 1 bus CAN information of floating differentiates the method for road traffic condition, it is characterized in that the average velocity computing method described in step (four) comprise the following steps;

After the invalid speed data of use rejects algorithm process, the speed data in SPEED file just can be used for calculating average velocity; The mode of operating speed integration carrys out accurate Calculation distance travelled, then in the cumulative sum divided by the time, finally draws the average velocity of traveling;

Calculate bus operating range SUM and be initialized as 0, the SUM that has no progeny in speed timer T generation is each time from adding the new stretch journey produced, and publicity is as shown in (I):

$\mathrm{SUM}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\underset{j=1}{\overset{m-1}{\mathrm{\Σ}}}\mathrm{\Δt}(v_j^i+v_{j+1}^i)/2---\left(I\right)$

Speed data in speed file SPEED is the approximately continuous rate curve increased progressively for the time interval with △ t on timestamp, but after being through the calculating of invalid speed data rejecting algorithm, approximately continuous rate curve can be cut into n the sub-curve of approximately continuous speed, and the outer cumulative sum that therefore SUM calculates is the calculated value of the sub-curve of cumulative single speed; For the sub-curve of each speed, due to continuous print two velocity amplitudes timestamp between difference be fixing, i.e. △ t, therefore, the method of infinitesimal analysis is used to calculate this section of distance, wherein i represents it is i-th sub-curve of speed, and j represents a jth speed data in the sub-curve of speed, and m is the number of speed data;

Calculating public transport becomes running time TIME to be initialized as 0, and at the TIME that has no progeny in speed timer T generation each time from adding the new one period of effective time produced, publicity is as shown in (II);

$\mathrm{TIME}=\underset{\mathrm{\σ}=1}{\overset{k}{\mathrm{\Σ}}}\mathrm{\Δt}(n_t^{\mathrm{\σ}}-n_d^{\mathrm{\σ}})---\left(\mathrm{II}\right)$

The calculating of time is also separated by speed timer T, has k speed timer interruption in driving process, be exactly the time therefore during the outer cumulative sum each timer timing that calculates of TIME, during each timing, total mistake there will be ^σn _tindividual speed data, and have after the invalid speed data of use rejects algorithm calculating ^σn _dindividual speed data is deleted, therefore effective time be △ t ( ^σn _t- ^σn _d);

After drawing SUM and TIME, the computing formula of average velocity AVG_SPEED is as shown in (III):

$\mathrm{AVG}\_\mathrm{SPEED}=\frac{\mathrm{SUM}}{\mathrm{TIME}}---\left(\mathrm{III}\right).$