Vehicle Dynamics And Test 车辆动力学和测试

CORRSYS-DATRONSensorsysteme GmbHwww.Corrsys-DVehicle dynamicswww.Corrsys-DVehicle dynamics Longitudinal Transversal Verticalwww.Corrsys-DLongitudinal dynamics Evaluation of accelerationand braking behavior Driving resistance: wheel, air,rising, and acceleration resistance(energy requirement) Engine characteristics,gear balance(engine supply)Planar model oflongitudinal dynamics Transmission of drive andbrake forces(driving limits)www.Corrsys-DTransversal dynamicsEvaluation of steering behaviortransversal acceleration ay RF = Rwww.Corrsys-DCORREVIT S - SensorsMeasured variables Vl = longitudinal velocity IVI = magnitude velocity Vt = transversal velocity = angleVlIVIVtwww.Corrsys-DAll in Onewww.Corrsys-DABS anti-lock braking systemThe main criteria for theassessment of ABS are: Steerability Stability Optimum braking distancewww.Corrsys-DImportant demands on ABS Steerability and driving stability must remain effectivewhen braking Steering response must minimized The control function must be OK over the entirespeed range. The system must provide optimum utilization of wheelgrip on the track surface; steerability must havepriority over reduction of braking distance.www.Corrsys-DGeneral control principles Single-wheel control:Each wheel has its own sensor that controls brake pressure exertedon the wheel to achieve maximum braking efficiency. Select-low control:The wheel with the least grip determines brake pressure exerted onboth wheels. Select-high control:The wheel with the most grip determines brake pressure exerted onboth wheels.www.Corrsys-DSensor list for ABSwww.Corrsys-DMeasured variable Sensor Axes Units Outputs Calibration factor Voltage range Mfgr.Wheel speed Wheel Pulse Transducer 4 km/h TTL Pulse ca. 500 Pulse/m 05 V CDSVehicle speed CORREVIT L-400 1 km/h CAN, TTL Pulse 460 Pulse/m 05 V CDSBrake pressure at wheels Pressure sensor 4 bar DMS CDSTire air valve: open/closed Switch/CAN-Bus 4 CAN signal 0 and 1CAN vehicle signalsBrake pedal position Linear Potentiometer 1 mm Analog 10 mV/mm 010 V CDSBrake pedal force Pedal Force Transducer 1 N Analog 1 mV/N 01.5 V CDSSlipWheel speed/Vehiclespeed % n/a Virtual channelsOptional:Yaw rate Gyro 1 /s Analog 56 mV/s 10 V CDSSteering wheel force MSW 1 Nm Analog, CAN 200 mV/Nm 10 V CDSSteering wheel angle MSW 1 Analog, CAN 8 mV/ 10 V CDSWheel slipDrive slip and brake slip are measured with:+Wheel Pulse Encoder CORREVIT L-400www.Corrsys-DFormula for wheel slipwww.Corrsys-DL400 Optical Sensorwww.Corrsys-DCORRSYS DATRONSENSORSYSTEMSFuel Consumption measurementwww.Corrsys-DDFL Fuel ConsumptionSystem Working principlewww.Corrsys-DCDS-DFL-WT: HeatExchanger Returned fuel is hot(used to cool injection(high pressure) pump At 70C without pressure1545% will vaporize -gas bubbles interfere withinjection system Compensation of pressurelossDFL-WTwww.Corrsys-DDAS3A Compact DataAqcuisition System Time, speed, distance, fuel volume, fuelconsumption, consumption per distance or per time Vehicle fuel efficiency ratings and valueswww.Corrsys-DInternational StandardsRoad vehicles Lateral transient response test methods open-loop test methods ISO 7401Passenger cars Braking in a turn- open loop test procedure ISO 7975Road vehicles Passenger car/trailer combinations Lateral stability test ISO 9815Road vehicles Measurement of road surface friction ISO 8349Passenger cars Steady-state circular driving behavior open-loop testprocedure ISO 4138Road vehicles Transient open-loop response test method with one period ofsinusoidal input ISO 8725Road vehicles Transient open-loop response test method with pseudo-randomsteering input ISO 8726Road vehicles Vehicle dynamics and road-holding ability Vocabulary ISO 8855www.Corrsys-DWhat is self-steeringbehavior?Self-steering is a set of vehicle steeringbehaviors that are of independent driversteering input!In the case of self-steering, the driver does not steer thevehicle, the steering angle does!Self-steering behavior is influenced by: Wheel load distribution Kinematics Suspension elasticity Wheel characteristicswww.Corrsys-DHow is self-steeringidentified?Steady-state, circular-course test driveMethodology: Constant radius Speed is increased from slow coasting If steering angle must be changed to maintainthe circular path, self-steering effects arepresentThe additional angle that the wheel is turned iscalled slip angle.www.Corrsys-DOversteer, understeer,neutral steeringOversteerUndersteerNeutralF RF = Rwww.Corrsys-Dcircular-course test drivewww.Corrsys-DSensor list for steady-state,Measured variable Sensor Axes Units Outputs Calibration factor Voltage range Mfgr.Slip angle CORREVIT S - 400 1 CAN, Analog 100 mV/ 10 V CDSLongitudinal & transversal speed CORREVIT S - 400 km/h CAN, Analog 100 mV/km/h 10 V CDSTire drift angle CORREVIT SF 2 CAN, Analog 100 mV/ 10 V CDSRoll angle HT 500 2 Anal