Summary of the invention
Purpose of the present invention just is to provide a kind of electric motor car driving process wireless test system, its data in can centering Large Electric car driving process, carry out data interaction by wireless communication unit, and data are unified collection, analysis and record, various test results in output electric motor car driving process are convenient to test run person and are observed.
The objective of the invention is to realize by such technical scheme, it includes sensor group, wireless communication unit, signals collecting mechanism and Signal Analysis System;
The sensor group is arranged in electric motor car to be measured, gathers the raw data in electric motor car driving process to be measured;
Wireless communication unit, the original data transmissions that the sensor group is collected is to signals collecting mechanism;
Signals collecting mechanism is used for the raw data that the receiving sensor group collects, and raw data is carried out data process, and the data after processing are stored and shown;
Signal Analysis System receives the data that signals collecting mechanism sends, and data is carried out analyzing and processing, outputs test result.
Further, described signals collecting mechanism includes the signals collecting initialization module, and the signals collecting initialization module is used for arranging collecting sensor signal passage, frequency acquisition, stored parameter and vehicle parameter; Vehicle parameter includes vehicle wheel roll radius, motor umber of pulse, wheel umber of pulse weekly weekly.
Further, described sensor group includes voltage sensor, current sensor, motor speed sensor, wheel speed sensor, environment temperature sensor, measuring point temperature sensor, equivalent acceleration transducer and driver behavior signal transducer; The driver behavior signal transducer includes accelerator pedal signal transducer, brake signal sensor and shift signal sensor.
Further, described Signal Analysis System includes the real-time computing module of road grade, and its gradient computing formula is:
Wherein: θ is the angle of gradient, a
eBe equivalent acceleration, i.e. acceleration transducer output valve, a is vehicle acceleration, g is acceleration of gravity.
Further, described Signal Analysis System includes the transmission state monitoring modular, be used for the monitoring gearshift procedure, motor speed and transmission gear ratio change continuously fast, calculate ratio of gear according to motor speed and vehicle wheel rotational speed, change and the monitoring of motor operating point transmission performance, duty and failure message according to speed ratio, calculate abrasion condition and ride comfort, the motor operating point includes current signal and tach signal.
Further, described Signal Analysis System includes the driving analysis module, according to accelerator pedal signal, brake signal and the shift signal in driving procedure, and the impact of analytical calculation driving habits on the vehicle mileages of continuation.
Further, described Signal Analysis System includes environment temperature and measuring point temperature test module, for specific road conditions, according to environment temperature and measuring point temperature, carries out the temperature rise performance evaluation.
Further, described Signal Analysis System includes the discharge capacity of the cell analysis module, calculates the actual discharge capacity of battery according to the change curve of electric current and voltage, analyzes the actual usability of battery.
Further, described Signal Analysis System includes the driving cycle analysis module, is used for the analytical calculation power of battery, machine operation point and electric efficiency, and utilizes the Vehicle Driving Cycle equation, estimates current condition of road surface.
Owing to having adopted technique scheme, the present invention has advantages of as follows:
The present invention can unify the various data that receiving sensor gathers, and records the various raw data that collect, and wireless communication module is sent to Signal Analysis System with the raw data that collects.For medium-and-large-sized electric motor car, the invention solves because vehicle body is larger, each sensor location is at the diverse location of vehicle, the problem that is difficult to connect up.The present invention is by arranging drainage pattern, and the passage, frequency and the data layout that can also uniform data gather make the data that collect can data synchronous, are convenient to data analysis work.Signal Analysis System, the data analysis that collects is processed, directly export the electric motor car test result, be convenient to test run person and observe, the analytic function of Signal Analysis System is powerful, can satisfy all test requests of electric motor car test, as required, can also edit test function, increase or the deletion test module, extendability is strong.
Other advantages of the present invention, target and feature will be set forth to a certain extent in the following description, and to a certain extent, based on being apparent to those skilled in the art to investigating hereinafter, perhaps can be instructed from the practice of the present invention.Target of the present invention and other advantages can realize and obtain by following instructions and claims.
Embodiment
The invention will be further described below in conjunction with drawings and Examples.
Electric motor car driving process wireless test system as shown in Figure 1, includes sensor group, wireless communication unit, signals collecting mechanism and Signal Analysis System;
The sensor group is arranged in electric motor car to be measured, gathers the raw data in electric motor car driving process to be measured.
Wireless communication unit, the original data transmissions that the sensor group is collected is to signals collecting mechanism.Wireless communication unit can comprise a signal receiver that is connected with signals collecting mechanism a plurality of wireless launchers that are connected with sensor.One or more sensors send to wireless receiver by a wireless launcher with data, then are sent to signal gathering unit, have solved the wiring problem of sensing data transmission line.
Signals collecting mechanism is used for the raw data that the receiving sensor group collects, and raw data is carried out data process, and the data after processing are stored and shown.
Signal Analysis System receives the data that signals collecting mechanism sends, and data is carried out analyzing and processing, outputs test result.Signal Analysis System can be independent host computer, and host computer and signals collecting mechanism carry out data transmission, also can be integrated in signals collecting mechanism.
Described signals collecting mechanism includes the signals collecting initialization module, and the signals collecting initialization module is used for arranging collecting sensor signal passage, frequency acquisition, stored parameter and vehicle parameter; Vehicle parameter includes vehicle wheel roll radius, motor umber of pulse, wheel umber of pulse weekly weekly.
Described sensor group includes voltage sensor, current sensor, motor speed sensor, wheel speed sensor, environment temperature sensor, measuring point temperature sensor, equivalent acceleration transducer and driver behavior signal transducer; The driver behavior signal transducer includes accelerator pedal signal transducer, brake signal sensor and shift signal sensor.
Common obliquity sensor and acceleration transducer on market, it is in fact equivalent acceleration transducer, its output signal is the stack of vehicle acceleration and road grade, can not be directly used in the road grade in the measuring vehicle driving process, can only be static and at the uniform velocity take measurement of an angle under state.The present invention measures equivalent acceleration transducer signals and vehicle wheel rotational speed signal simultaneously, and the real-time computing module of road grade calculates vehicle acceleration according to the rate of change of vehicle wheel rotational speed, the signal of equivalent acceleration transducer is deducted the factor of vehicle acceleration.Can calculate road grade, its gradient computing formula is:
Wherein: θ is the angle of gradient, a
eBe equivalent acceleration, i.e. acceleration transducer output valve, a is vehicle acceleration, g is acceleration of gravity.
The transmission state monitoring modular, be used for the monitoring gearshift procedure, motor speed and transmission gear ratio change continuously fast, calculate ratio of gear according to motor speed and vehicle wheel rotational speed, change and the monitoring of motor operating point transmission performance, duty and failure message according to speed ratio, calculate abrasion condition and ride comfort, the motor operating point includes current signal and tach signal.
The test of the mileages of continuation of present electric motor car single charge is more extensive, is travelled in particular link by the driver, when battery undervoltage, records mileages of continuation.Because the factors such as number of times of operating habit, speed of operation and braking have material impact to mileages of continuation, driving analysis module of the present invention, can be according to accelerator pedal signal, brake signal and the shift signal in driving procedure, the impact of analytical calculation driving habits on the vehicle mileages of continuation.
The test of standard mileages of continuation:
Select good road, take straight road as main; After vehicle launch, accelerator pedal remains on the fixed position as far as possible, such as, travel with stabilizing speed in the position of corresponding level road 25km/h; Adopt in advance the mode that slides when needing to slow down, do not brake as far as possible; Stop after battery undervoltage, calculate from starting to the mileages of continuation of parking, be called the standard mileages of continuation.
Mileages of continuation test under complex road condition:
The driver travels under the various road conditions of appointment, records driving process.
For example, under the complex road condition of urban district, the stream of people and vehicle flowrate are large, and traffic lights are many, and the driver needs frequent starting and brake, but start each time brake or stop on the impact of mileages of continuation according to the following formula simple method of estimation.
Wherein: △ S is average each mileages of continuation that starts brake or stop and reduce, S
rBe standard mileages of continuation, S
rBe the mileages of continuation of urban district complex road condition, n
stBe the number of times that starts brake or stop.
For example, the category of roads of suburb country is lower, and stone road or dirt road are more, pavement roughness, and the road resistance to rolling is large, and the speed of a motor vehicle is not high, so the proportion of windage is lower, although driver's accelerator pedal constantly changes, the brake situation is less.Can estimate bad road surface to the impact of mileages of continuation according to following formula, consider that mainly road resistance and the speed of a motor vehicle change the energy that consumes, ignore the impact of windage, therefore bad road surface takes percentage recently to represent on the impact of distance travelled,
Wherein: △ ε is the ratio of the mileages of continuation that reduces on bad road surface of travelling, S
rBe standard mileages of continuation, S
rBe the mileages of continuation under poor road.
For example, gear has material impact to mileages of continuation, and present electric automobile has disposes mechanical transmission, usually is provided with 2-3 gear, and the speed of a motor vehicle of each gear is different.Take the at present common Minitype electric automobile with 2 gears as example, 1 speed of keeping off a car is minimum, and max. speed is 20-25km/h usually, and 2 gear max. speed are 45-60km/h approximately.The speed of a motor vehicle is higher, and mileages of continuation is shorter.Gear is separately fixed at different gears, and the test mileages of continuation can be investigated gear to the concrete impact of mileages of continuation.
Environment temperature and measuring point temperature test module for specific road conditions, according to environment temperature and measuring point temperature, are carried out the temperature rise performance evaluation.Specific road conditions are the specific road conditions such as level road, ramp, frequent starting.
The discharge capacity of the cell analysis module calculates the actual discharge capacity of battery according to the change curve of electric current and voltage, analyze the actual usability of battery.
The driving cycle analysis module is used for the analytical calculation power of battery, machine operation point and electric efficiency, and utilizes the Vehicle Driving Cycle equation, estimates current condition of road surface.
Determine the duty of each parts and derive road condition according to the signal of test, process is as follows:
Calculate the power of battery:
P
bat=U
batI
bat
Wherein: P
batBe the power of battery, U
batBe cell voltage, I
batBe battery current.
Determine the machine operation point:
According to battery current, i.e. the working current of motor and motor speed n
m, look into the machine operation performance plot and determine the machine operation point, obtain Motor torque T
mWith electric efficiency η
m
Calculate the speed of a motor vehicle, vehicle acceleration, the gradient, vehicle drive force:
u
a=0.3768n
rr
Wherein: u
aBe the speed of a motor vehicle, n
rBe vehicle wheel rotational speed, vehicle wheel rotational speed n
rWith motor speed n
mProportional, scale-up factor is by the speed ratio i decision of the variator of vehicle, and η is transmission efficiency, and r is vehicle wheel roll radius, and t is the time, and △ t is the speed data collection time interval, F
rBe vehicle drive force.
Analyze the Vehicle Driving Cycle equation:
Wherein: F
rBe rolling resistance coefficient, m is complete vehicle weight, comprises driver weight, C
dBe air resistance coefficient, A is front face area.
In this formula, complete vehicle weight m can measure; Air resistance coefficient C
d, front face area A determines by vehicle; Only have rolling resistance coefficient unknown, therefore can utilize this formula to calculate rolling resistance coefficient.
For the vehicle that has, do not provide air resistance coefficient C
d, can test in straight good road surface and obtain air resistance coefficient C
d, method is as follows:
1) test coefficient of rolling resistance
Select straight good road surface, vehicle is in the low-speed stable running status, and vehicle-speed limit is ignored windage below 5km/h, and the equation formula is reduced to
F
r=fmg
Utilize this formula can calculate coefficient of rolling resistance.
2) calculate air resistance coefficient
At the level road high-speed stable running, the equation formula is reduced to
Utilize this formula can calculate air resistance coefficient.
Testing process of the present invention as shown in Figure 2, concrete steps are:
1) signals collecting mechanism is connected with the sensor group;
2) initializing signal collecting mechanism;
3) enabling signal collecting mechanism carries out data acquisition;
4) data that collect of Signal Analysis System analytic signal collecting mechanism, output test result.
Signal Analysis System can be arranged on the host computer of a platform independent, this host computer can be selected to be connected with signals collecting mechanism in test process, in signals collecting, signal is analyzed, be connected with signals collecting mechanism after also can being chosen in test and finishing, all signals that gather are carried out disposable analysis.
Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although with reference to preferred embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not breaking away from aim and the scope of the technical program, it all should be encompassed in the middle of claim scope of the present invention.