A kind of speed-measuring method based on train multisensor velocity-measuring system
Technical field
The present invention relates to a kind of speed-measuring method of velocity-measuring system, espespecially a kind of speed-measuring method based on train multisensor velocity-measuring system.
Background technology
Along with developing rapidly of urban track traffic, punctual, low operation interval becomes developing goal, therefore requires signal system to have robotization and the intellectuality of height.Signal system nucleus equipment is the safe operation that vehicle-mounted automatic protective system (hereinafter referred is ATP) ensures track traffic.
Vehicle-mounted ATP equipment, by gathering the control informations such as current train speed, the speed transmitting according to ground control equipment, prevents train hypervelocity and rushes the hazard events such as signal.And all safeguard function benchmark of vehicle-mounted ATP equipment are that the speed gathering must be reliable, truly reflect current speed.Therefore generally adopt Negotiation speed sensor to carry out accurate test speed.
The number of revolutions of the principle of wheel shaft impulse speed sensor (hereinafter referred speed pickup) based on detecting wheel accurately calculates speed.When wheel spin or when skidding (hereinafter referred empty sliding), easily occur testing the speed inaccurate.General way is carried out subsidiary by appending other a speed measuring equipment, judges whether occur idle running or skid.
A kind of way can be assisted and test the speed according to installation radar.Exceed certain amplitude when the speed of speed pickup speed and radar differs, think and enter idle running or skid, now will not be as the criterion with speed pickup speed.The radar sensor good stability that tests the speed, but rate accuracy is high not as good as speed pickup.Obtain true velocity so speed pickup is generally used for, and whether radar sensor is normal for detection of speed sensor velocity measurement.When speed pickup and radar velocity measurement are when roughly the same, the result that tests the speed of operating speed sensor, otherwise use the result that tests the speed of radar sensor as the result that tests the speed after merging.
Under normal circumstances, radar can both provide the train speed of compared with normal.Test the speed resultant error within the specific limits time, the speed of operating speed sensor, otherwise use the speed of radar as the result that tests the speed when speed pickup and radar sensor.But in use we find, in few situation, as the inclement weather such as heavy rain, heavy snow, or disturbed by other environmental factors, testing the speed of radar also can be received impact, gives the result that tests the speed making mistake.Because radar and speed sensor velocity measurement result can be used the result that tests the speed of radar when inconsistent, thus caused serious test the speed inaccurate.
Summary of the invention
The problem existing for prior art, the object of the present invention is to provide a kind of speed-measuring method that improves velocity-measuring system rate accuracy.
Whether for achieving the above object, the speed-measuring method based on train multisensor velocity-measuring system of the present invention, comprises the following steps: 1) detect radar sensor and test the speed abnormal; 2) if detect that radar sensor tests the speed normally, carries out locomotive velocity measuring by conventional speed-measuring method; 3), if detect that radar sensor tests the speed extremely, then whether detection speed sensor tests the speed and occurs extremely; 4) if detect that speed sensor velocity measurement is normal, the result that tests the speed of operating speed sensor.
Further, in step 1), the detection method of radar sensor is specially: the First Speed difference of calculating forward and backward output according to the velocity amplitude of the forward and backward output of radar sensor, and judge whether this First Speed difference exceeds velocity jump threshold range, then judge according to result whether radar sensor tests the speed abnormal.
Further, the velocity amplitude of the forward and backward output of described radar sensor is discrete, and only radar sensor is carried out to one-time detection, and select the interval time of forward and backward output speed value according to actual conditions.
Further, if described First Speed difference exceeds described velocity jump threshold range, judge that radar sensor tests the speed extremely, does not use the result that tests the speed of radar sensor.
Further, the velocity amplitude of the forward and backward output of described radar sensor is continuous, and in the given time radar sensor is carried out to repeated detection, number of times and predefined threshold value comparison by repeated detection to radar sensor generation saltus step, if repeated detection exceeds predefined threshold value to the number of times of radar sensor generation saltus step, judge that radar sensor tests the speed extremely, otherwise judge that radar sensor tests the speed normally.
Further, the detection method of step 3) medium velocity sensor is specially: calculate the second speed difference between each speed pickup according to the velocity amplitude of each speed pickup output, and judge whether this second speed difference exceeds velocity jump threshold range, then judge that according to result whether speed sensor velocity measurement is abnormal.
Further, if described second speed difference exceeds described velocity jump threshold range, judge that speed sensor velocity measurement is abnormal, fault tests the speed.
Further, described velocity jump threshold range is [– (b × t+ ε), a × t+ ε], the maximum traction acceleration that wherein a is train, b is maximum braking ratio, and t is the cycle of operation, and ε is radar velocity measurement fluctuation parameters.
Speed-measuring method based on train multisensor velocity-measuring system of the present invention, according to train performance parameter, radar sensor and speed pickup are added to the result saltus step protection of testing the speed, if test the speed result generation saltus step, think that the current device result that tests the speed is undesired, do not use the current device result that tests the speed.Can avoid in the abnormal situation of radar work, velocity-measuring system misidentification speed pickup skids or dallies, using radar sensor degree of being tested the speed as Output rusults, cause velocity-measuring system to test the speed inaccurate.By to the inconsistent detection of radar velocity measurement result and processing, ensure the security of system, also improve the availability of system.
Brief description of the drawings
Fig. 1 is the multisensor velocity-measuring system that the present invention is based on train schematic diagram that tests the speed;
Fig. 2 detects the whether abnormal process flow diagram of radar sensor in speed-measuring method of the present invention;
Fig. 3 is the whether abnormal process flow diagram of detection speed sensor in speed-measuring method of the present invention.
Embodiment
Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples are used for illustrating the present invention, but do not limit the scope of the invention.
As shown in Figure 1, the multisensor velocity-measuring system based on train of the present invention, mainly comprises radar sensor, speed pickup 1 and speed pickup 2, and it is empty sliding that radar sensor is mainly used in judging whether speed pickup occurs.Velocity-measuring system in the present embodiment adopts two speed pickups, stable, reliable for what ensure to test the speed, velocity-measuring system also can adopt multiple speed pickups, it is empty sliding that radar sensor goes to judge whether each speed pickup occurs one by one, and velocity-measuring system is finally using mean value that empty sliding velocity amplitude that speed pickup is surveyed does not occur as output speed.And occur when abnormal when radar sensor self tests the speed, cannot correctly judge whether speed pickup empty cunning has occurred by radar sensor, likely because radar sensor institute degree of testing the speed differs greatly with speed pickup degree of testing the speed, and all there is empty cunning in erroneous judgement speed pickup, final velocity-measuring system can be exported the speed of radar sensor, but now radar sensor degree of testing the speed substantial deviation the actual speed of train, cause velocity-measuring system output speed seriously inaccurate.
For the problems referred to above, the present invention is based on the speed-measuring method of train multisensor velocity-measuring system, comprise the following steps:
1) detect the whether abnormal step of radar sensor following (treatment scheme is shown in Fig. 2):
Record radar sensor output speed last time value, whether normal for detection of the velocity amplitude of this output of radar sensor.Calculate the speed of this output and the speed difference of output last time, and judge whether this difference exceeds threshold range (hereinafter referred to as velocity jump thresholding).If in threshold range, think that radar velocity measurement is normal, can test the speed according to conventional speed-measuring method, as compared radar sensor speed and speed pickup speed, in threshold range, velocity-measuring system operating speed sensor speed, as output speed, otherwise is used radar sensor speed as output speed.If the speed difference of the forward and backward output of radar sensor not in threshold range, is thought that radar sensor tests the speed and is occurred saltus step, continue follow-up speed measurement treatment step, the speed of described forward and backward output can be continuous can be also discrete.In order to prevent that extraneous factor from causing radar sensor to occur the jump of testing the speed of moment, have influence on the availability of system, can also increase continuous transition detection detecting in the abnormal step of radar sensor.Within the time of setting, radar sensor is carried out to transition detection repeatedly, record testing result repeatedly, and number of times and predefined threshold value comparison that radar sensor saltus step occurs detected in during this period of time, just think that radar sensor occurs extremely if exceed threshold value, otherwise thinking that radar sensor is normal, is the saltus step of testing the speed moment.Setting-up time and the predefined threshold value of transition detection are determined by reality continuously, can select flexibly.
There is the saltus step of testing the speed of moment for fear of radar sensor, selectively, the speed of the forward and backward output of radar sensor record is discrete, the speed that records forward and backward output extends certain hour, for example, the 1st second record output radar sensor speed, after being separated by 2 seconds, radar sensor speed exported in record again.Only carry out one-time detection although whether radar sensor velocity jump is occurred to, but due to forward and backward tested the speed degree certain interval of time, also can avoid radar sensor to occur the moment saltus step of testing the speed, think that radar sensor occurs abnormal, have influence on the availability of system.Wherein, the speed time expand of forward and backward output, can be selected flexibly by actual conditions.
Velocity jump threshold range computing method are as follows:
If the maximum of train traction acceleration a, maximum braking ratio is b, and the cycle of operation is t, and velocity jump threshold range should be: [– (b × t+ ε), a × t+ ε], wherein, ε is radar velocity measurement fluctuation parameters.Above-mentioned Train Parameters is provided by producer after train dispatches from the factory.
2) the whether abnormal step following (treatment scheme is shown in Fig. 3) of detection speed sensor
When detecting that radar sensor tests the speed extremely, cannot carry out detection speed sensor with radar sensor and whether idle running has occurred or slided.Now need to judge and test the speed difference whether in velocity jump threshold range between two speed pickups.If, still think test the speed normal, the mean value of output two speed pickup degree of testing the speed, otherwise, think the fault that tests the speed.
Above embodiment is only for illustrating the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; without departing from the spirit and scope of the present invention; can also make a variety of changes and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.