Vehicle Dynamics And Test 车辆动力学和测试

www.Corrsys-DCORRSYS-DATRONSensorsysteme GmbHwww.Corrsys-DVehicle dynamicswww.Corrsys-DVehicle dynamics Longitudinal Transversal VerticalLongitudinal dynamics Evaluation of accelerationand braking behavior Driving resistance: wheel, air,rising, and acceleration resistance(energy requirement) Engine characteristics,gear balance(engine supply) Transmission of drive andbrake forces(driving limits)www.Corrsys-DPlanar model oflongitudinal dynamicsTransversal dynamicsEvaluation of steering behaviortransversal acceleration a y R F = ROversteer, understeer,neutral steeringCORREVIT S - SensorsV twww.Corrsys-DIVIMeasured variables V l = longitudinal velocity IVI = magnitude velocity V t = transversal velocity = angleV lwww.Corrsys-DAll in OneABS anti-lock braking systemThe main criteria for theassessment of ABS are: Steerability Stability Optimum braking distancewww.Corrsys-Dwww.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.Measuredvariable Sensor Axes Units Outputs Calibrationfactor Voltagerange Mfgr.Wheelspeed WheelPulseTransducer 4 km/h TTLPulse ca.500Pulse/m 05V CDSVehiclespeed CORREVITL-400 1 km/h CAN,TTLPulse 460Pulse/m 05V CDSBrakepressureatwheels Pressuresensor 4 bar DMS CDSTireairvalve:open/closed Switch/CAN-Bus 4 CANsignal 0and1CANvehiclesignalsBrakepedalposition LinearPotentiometer 1 mm Analog 10mV/mm 010V CDSBrakepedalforce PedalForceTransducer 1 N Analog 1mV/N 01.5V CDSSlip Wheelspeed/Vehiclespeed % n/a VirtualchannelsOptional:Yawrate Gyro 1 /s Analog 56mV/s 10V CDSSteeringwheelforce MSW 1 Nm Analog,CAN 200mV/Nm 10V CDSSteeringwheelangle MSW 1 Analog,CAN 8mV/ 10V CDSwww.Corrsys-DSensor list for ABSWheel slipDrive slip and brake slip are measured with:+Wheel Pulse Encoder CORREVIT L-400www.Corrsys-Dwww.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-WTDAS3A 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-Dwww.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-DOversteerUndersteerNeutral F R F = ROversteer, understeer,neutral steeringMeasuredvariable Sensor Axes Units Outputs Calibrationfactor Voltagerange Mfgr.Slipangle CORREVITS-400 1 CAN,Analog 100mV/ 10V CDSLongitudinal&transversalspeed CORREVITS-400 km/h CAN,Analog 100mV/km/h 10V CDSTiredriftangle CORREVITSF 2 CAN,Analog 100mV/ 10V CDSRollangle HT500 2 Analog 20mV/mm 010V CDSSteeringwheelangle MSW 1 CAN,Analog 8mV/ 10V CDSSteeringwheeltorque MSW Nm CAN,Analog 200mV/Nm 10V CDSYawrate Gyro 1 /s Analog 56mV/s 10V CDSLongitudinal&transversalacceleration Acceleration-Sensor 1 g Analog 2V/g 0.54.5V CDSwww.Corrsys-DSensor list for steady-state,circular-course test drivewww.Corrsys-D Presentation of results, steering wheel angle overlateral acceleration in right turn and left turn Sideslip angle over lateral acceleration in right turnand left turn Roll angle over lateral acceleration in right turn andleft turn St