Division Mobile Working Machinery Prof. Dr.-Ing. Dr. h.c. K.-Th. Renius c/o Institute of Automotive Engineering Prof. Dr.-Ing. B. Heißing Technische Universität München Control and Operating Behavior of Continuously Variable Chain Transmissions 2004 International Continuously Variable and Hybrid Transmission Congress September 23-25, 2004 Roland Mölle

Mölle 2004 Introduction – Chain-CVT Summary Clamping Systems Ratio Control Design during Range Shifts in Autarkic Hybrid Expanded Control Layout for Universal Use in Chain Variator Applications Presentation Outline

Mölle 2004 Introduction Chain Hydro-Mechanical Torque Sensor Secondary Pulley Primary Pulley PIV Chain Converter

Mölle 2004 Typical CVT chain of a modern passenger car: Audi multitronic Torque Capacity up to 300 Nm Nominal Power 162 kW (V6-3.0) Pull type Chain in Audi/LuK CVT

Mölle 2004 BrandModelEngine Maximum Torque Transmission ratio (Variator, Overall) Type of Variator AudiA44-Zyl., 2,0 l, 96 kW195 Nm?Pull Type Chain AudiA46-Zyl., 3,0 l, 162 kW300 Nm?Pull Type Chain AudiA64-Zyl., 1,8 l, 110 kW210 Nm2,4 - 0,4; 6,0Pull Type Chain AudiA66-Zyl., 2,4 l, 121 kW230 Nm2,4 - 0,4; 6,0Pull Type Chain AudiA66-Zyl., 2,8 l, 142 kW280 Nm2,4 - 0,4; 5,3Pull Type Chain DaewooMatiz3-Zyl., 0,8 l, 38 kW69 Nm?Push Belt DaihatsuCuore3-Zyl., 0,7 l, 43 kW64 Nm2,27 - 0,55; 6,77Push Belt FiatPunto4-Zyl., 1,2 l, 59 kW114 Nm2,43 - 0,44; 5,25Push Belt HondaLogo4-Zyl., 1,3 l, 48 kW108 Nm2,47 - 0,45; 6,36Push Belt HondaInsight3-Zyl., 1,0 l, 50 kW91 Nm2,44 - 0,41; 5,69Push Belt HondaCivic4-Zyl., 1,4 l, 66 kW130 Nm2,47 - 0,45; 5,81Push Belt HondaCivic4-Zyl., 1,6 l, 81 kW152 Nm2,47 - 0,45; 5,81Push Belt HondaCivic4-Zyl., 1,7 l, 85 kW149 Nm2,47 - 0,45; 5,81Push Belt HondaCapa4-Zyl., 1,5 l, 72 kW133 Nm2,47 - 0,45; 6,34Push Belt HondaHR-V4-Zyl., 1,6 l, 77 kW135 Nm2,47 - 0,45; 6,88Push Belt HondaHR-V4-Zyl., 1,6 l, 92 kW144 Nm2,47 - 0,45; 6,88Push Belt Mazda1214-Zyl., 1,2 l, 55 kW110 Nm3,84 - 0,66; 3,84Push Belt MGMGF4-Zyl., 1,8 l, 88 kW165 Nm2,42 - 0,52; 4,05Push Belt CVT Passenger Cars (worldwide, 2001)

Mölle 2004 BrandModelEngine Maximum Torque Transmission ratio (Variator, Overall) Type of Variator MiniCooper4-Zyl., 1,6 l, 85 kW149 Nm?Push Belt MitsubishiLancer Cedia4-Zyl., 1,8 l, 96 kW177 Nm2,32 - 0,45; 5,22Push Belt NissanMicra/March4-Zyl., 1,0 l, 44 kW80 Nm2,43 - 0,44; 6,3Push Belt NissanMicra/March4-Zyl., 1,4 l, 60 kW108 Nm2,43 - 0,44; 5,25Push Belt NissanCube4-Zyl., 1,3 l, 63 kW120 Nm2,43 - 0,44; 5,24Push Belt NissanBluebird4-Zyl., 2,0 l, 110 kW200 Nm?Push Belt NissanAlmera Tino4-Zyl., 2,0 l, 100 kW175 Nm2,33 - 0,43; 5,47Push Belt NissanPrimera4-Zyl., 2,0 l, 103 kW181 Nm2,33 - 0,43; 4,18Push Belt NissanPrimera '024-Zyl., 2,0 l, 110 kW200 Nm2,33 - 0,43; 5,47Push Belt NissanPrimera '024-Zyl., 2,0 l, 125 kW245 Nm2,1 - 0,43; 5,47Push Belt NissanPrairie/Liberty4-Zyl., 2,0 l, 103 kW186 Nm2,33 - 0,43; 5,47Push Belt NissanSerena4-Zyl., 2,0 l, 107 kW186 Nm2,33 - 0,43; 5,74Push Belt NissanCedric/Gloria6-Zyl., 3,0 l, 206 kW388 Nm2,86 - 0,66; 3,69Half Toroid RoverR454-Zyl., 1,8 l, 86 kW160 Nm2,42 - 0,44; 5,76Push Belt SubaruPleo4-Zyl., 0,7 l, 33 kW56 Nm2,43 - 0,44; 4,67Push Belt SuzukiAlto/Kei3-Zyl., 0,7 l, 34 kW57 Nm2,42 - 0,55; 6,77Push Belt ToyotaOpa4-Zyl., 2,0 l, 112 kW200 Nm2,4 - 0,43; 5,18Push Belt CVT Passenger Cars (worldwide, 2001)

Mölle 2004 Introduction – Chain-CVT Summary Clamping Systems Control Design for Range Shifts in Autarkic Hybrid Expanded Control Layout for Universal Use in Chain Variator Applications Presentation Outline

Mölle 2004 Constant Pressure System Oil flow on demand Torque information supplied by engine controller: Poor dynamics and limited accuracy Need for high over clamping for security reasons or additional measures Oil flow always at maximum pressure level Main Advantage: Disadvantages: Pulley 1 Pulley 2 Constant Pressure Oil Supply Pressure Transducer Directional Control Valve

Mölle 2004 Constant Flow Oil supply Pulley 1 Pulley 2 Hydraulic Control Unit Four Edges Torque Sensor Actuator Speed Ratio Control Pressure Differential Valve Line Pressure Valve Constant Oil Flow System (PIV) Clamping pressures are automatically achieved without superior control High dynamically set clamping pressures due to the “pump function” Clamping pressure and speed ratio control independent Permanent, constant oil flow required Advantages: Main Disadvantage: Spool Valve

Mölle 2004 Conventional Torque Sensor (System PIV) Torque sensor pressure – proportional to torque at the shaft Characteristics: s F (axial movement of sensorplate) Movable sensor plate Additional “pump function” at high torque gradients

Mölle 2004 Characteristic Curve of Actuator in Conventional PIV Clamping Systems shift speed ds/dt ,5-0,500,51,5 Slide valve travel P r e s s u r e bar mm Pcyl1Pcyl2 pTorquePump p CYL1 p CYL2 p TORQUE p PUMP Torque Nm 400

Mölle 2004 Introduction – Chain-CVT Summary Clamping Systems Control Design for Range Shifts in Autarkic Hybrid Expanded Control Layout for Universal Use in Chain Variator Applications Presentation Outline

Mölle 2004 Driveline of the Autarkic Hybrid The Autarkic Hybrid  Opel Astra Caravan  60 kW Diesel engine  10 kW electric motor (120V)  i 2 -CVT gearbox Range shift in Autarkic Hybrid raised the need for improved speed ratio control: Extremely high torque gradients during range shift (CVT engaged vs. disengaged) Error signal <0,002 required

Mölle 2004 CVT Controller, Variable in Structure   Absolute value of deviation Algebraic sign of deviation Selection of control parameters: 0  Value of control variable Variation of param. (gain scheduling):

Mölle 2004 Influence of Disturbance Variables Ratio of clamping forces  F An F Ab = F Ab =p Ab. A z F An =p An. A z p An AzAz AzAz p Ab Main disturbance variables: Torque Speed Ratio... lead to a change in required  -ratio for steady state operation

Mölle 2004 Extension of the Speed Ratio Controller Problem: Improved control system is needed for speed ratio control at SYN (i=0,458) during range shift. Solution: Disturbance feedforward (torque)

Mölle 2004 Extension of the Speed Ratio Controller

Mölle 2004 Results and further Aims The taken measures resulted in a significant improvement of the quality of speed ratio control and reliability of range shifts. Apply same principles to the CVT controller for universal use:  Regard to further disturbance variables  Improved control over the whole spreading range (improvements in quality, efficiency etc.)  Enable different control strategies: ratio based strategies (e.g. ground speed pto) vs. di/dt control (passenger car / transportation work)

Mölle 2004 Introduction – Chain-CVT Summary Clamping Systems Control Design for Range Shifts in Autarkic Hybrid Expanded Control Layout for Universal Use in Chain Variator Applications Presentation Outline

Mölle 2004 Further disturbance variables: Speed (rotating hydraulic cylinder) Spring (basic clamping force) Characteristic  -map Disturbance Variables Algebraic compensation Main disturbance variables torque and speed ratio lead to: Pulley Misalignment, shaft deflection, pulley distortion, … … change in clamping force ratio

Mölle 2004 setpoint CVT Extension of the Control Structure Distrubance feedforward Disturbance Variables actual value  -map Mathematic Compensation E=mc 2 Linear Controller

Mölle 2004 setpoint CVT Adaptation of  -map Distrubance feedforward Disturbance Variables actual value Adaptation  -map Mathematic Compensation E=mc 2  Steady state (T, n, manipulated var.)  … Prerequisites for adaptation: background task (duration ?) constant task time (e.g. 5ms) Linear Controller Question: Where to get the  -map from ? Output of Linear Controller supposed to be Zero in steady state!

Mölle 2004 Adaptation Law Weighting functions: Gauss Cone... Adaptation of the sampling points: Value of the manipulated variable from linear controller x weighting factor.

Mölle 2004 START Visualization and Discussion of the Adaptation Process

Mölle 2004 CVT in Drive Train Configuration  Power demand leads to desired engine speed.  New engine speed is achieved by changing the CVT’s speed ratio i.  Change in speed ratio di/dt affects the available torque at the wheel T 2 !  Controlling the rate of speed ratio change is favorable

Mölle 2004 Control of the Rate of Speed Ratio Change di/dt CVT Distrubance feedforward Disturbance Variables  -map Mathematic Compensation E=mc 2 Modification of the control structure: Adaptation Linear Controller  Stop Adaptation Process  Delete Feedback Loop  Replace Controller f(di/dt,n, geometry) setpoint di/dt p dyn di/dt setpoint speed ratio

Mölle 2004 Control of the Rate of Speed Ratio Change di/dt p dyn = ds/dt / ( A CYL · D )  Axial pulley speed ds/dt = f ( di/dt, geometry )  Damping coefficient D = f ( speed… ) * ü = 1/i

Mölle 2004 Measured Results of the Control of Speed Ratio Change ds/dt

Mölle 2004 Introduction – Chain-CVT Summary Clamping Systems Control Design for Range Shifts in Autarkic Hybrid Expanded Control Layout for Universal Use in Chain Variator Applications Presentation Outline

Mölle 2004 Summary  Quality of speed ratio control was significantly improved  The control structure was implemented using a RCP- system running under Matlab/Simulink (xPCTarget) and is currently running on a test rig  For use in tractor applications it was also implemented on a typical electronic control unit (C167) both manually and using code generation (dSpaceTargetLink 2.0)C167  Gathered  -maps can be used for different purposes (scientific work, onboard diagnostic purposes etc.)  Further optimization possible (improved di/dt,  -max)

Division Mobile Working Machinery Prof. Dr.-Ing. Dr. h.c. K.-Th. Renius c/o Institute of Automotive Engineering Prof. Dr.-Ing. B. Heißing Technische Universität München Control and Operating Behavior of Continuously Variable Chain Transmissions 2004 International Continuously Variable and Hybrid Transmission Congress September 23-25, 2004 Roland Mölle

Mölle 2004