用于计算轮轨关系的matlab程序

% M-file name: wheelset.m % M-file type: Function file % This function file identifies the single-point (tread contact) and the two-point (tread and flange contact) %equations that constitute the mathematical model for the dynamics of a single % wheelset rolling on a straight track. The equations are written in state space form. % This function is called by the function file 'equations.m' for solving the differential equations % constituting the motion of wheelset. The wheelset lateral and yaw displacements and % velocities, and the left and right rail lateral displacements are provided as inputs to this % function in order to solve for the wheelset. Additionally, the wheelset suspension forces and % moments are provided as inputs. % This function calls the following functions % 'rolling_radius', 'contact_angle', 'onept_creep', 'onept_normal', 'twopt_creep', and % 'twopt_normal'. function [xdot1,xdot2,xdot3,xdot4,xdot5,xdot6,phi]=wheelset(x1,x2,x3,x4,x5,x6,Fsuspyw,Msuspzw) % Parameters used for simulation % V: Forward velocity of wheelset (m/sec) % lambda: wheel conicity % a: wheel base (m) % r0: Centered rolling radius of the wheel (m) % yfc: Flange clearance or flange width (m) % yfctol: Lateral tolerance added to yfc in order to facilitate numerical simulation (m) % mw: Mass of wheelset (kg) % Iwz: Yaw principal mass moment of inertia of wheelset (kg-m2) % Iwy: Pitch principal mass moment of inertia of wheelset (kg-m2) % krail: Effective lateral stiffness of rail (N/m) % crail: Effective lateral damping of rail (N/m) % g: Acceleration due to gravity (m/s2) % Indicating the global nature of the variables. This means that the value of the variables need % not be specified in this function file. This value is automatically obtained from the main file % 'single_wheelset.m'. global V lambda a r0 yfc yfctol mw Iwz Iwy krail crail g; % Nomenclature: % rlt: Rolling radius at left wheel tread contact patch % rlf: Rolling radius at left wheel flange contact patch % rrt: Rolling radius at right wheel tread contact patch % rrf: Rolling radius at right wheel flange contact patch % deltalt: Contact angle at left wheel tread contact patch % deltalf: Contact angle at left wheel flange contact patch % deltart: Contact angle at right wheel tread contact patch % deltarf: Contact angle at right wheel flange contact patch % rl: Rolling radius at left wheel contact patch (for single-point contact) % rr: Rolling radius at right wheel contact patch (for single-point contact) % deltal: Effective contact angle at left wheel contact patch after compensating for wheelset roll % angle (for single-point contact) % deltatl: Effective contact angle at left wheel tread contact patch after compensating for % wheelset roll angle (for two-point contact) % deltafl: Effective contact angle at left wheel flange contact patch after compensating for % wheelset roll angle (for two-point contact) % deltar: Effective contact angle at right wheel contact patch after compensating for wheelset % roll angle (for single-point contact) % deltatr: Effective contact angle at right wheel tread contact patch after compensating for % wheelset roll angle (for two-point contact) % deltafr: Effective contact angle at right wheel flange contact patch after compensating for % wheelset roll angle (for two-point contact) % lambdal: Slope of tangent at left wheel contact patch (for single-point contact) % lambdalt: Slope of tangent at left wheel tread contact patch (for two-point contact) % lambdalf: Slope of tangent at left wheel flange contact patch (for two-point contact) % lambdar: Slope of tangent at right wheel contact patch (for single-point contact) % lambdart: Slope of tangent at right wheel tread contact patch (for two-point contact) % lambdarf: Slope of tangent at right wheel flange contact patch (for two-point contact) % phi: Wheelset roll angle % dphi: Rate of change of wheelset roll angle % etaxl: Longitudinal creepage at left wheel contact patch (for single-point contact) % etaxlt: Longitudinal creepage at left wheel tread contact patch (for two-point contact) % etaxlf: Longitudinal creepage at left wheel flange contact patch (for two-point contact) % etayl: Lateral creepage at left wheel contact patch (for single-point contact) % etaylt: Lateral creepage at left wheel tread contact patch (for two-point contact) % etaylf: Lateral creepage at left wheel flange contact patch (for two-point contact) % etaspl: Spin creepage at left wheel contact patch (for single-point contact) % etasplt: Spin creepage at left wheel tread contact patch (for two-point contact) % etasplf: Spin creepage at left wheel flange contact patch (for two-point contact) % etaxr: Longitudinal creepage at right wheel contact patch (for single-point contact) % etaxrt: Longitudinal creepage at right wheel tread contact patch (for two-point contact) % etaxrf: Longitudinal creepage at right wheel flange contact patch (for two-point contact) % etayr: Lateral creepage at right wheel contact patch (for single-point contact) % etayrt: Lateral creepage at right wheel tread contact patch (for two-point contact) % etayrf: Lateral creepage at right wheel flange contact patch (for two-point contact) % etaspr: Spin creepage at right wheel contact patch (for single-point contact) % etasprt: Spin creepage at right wheel tread contact patch (for two-point contact) % etasprf: Spin creepage at right wheel flange contact patch (for two-point contact) % Fcxl: Longitudinal creep force on left wheel contact patch (for single-point contact) % Fcxlt: Longitudinal creep force on left wheel tread contact patch (for two-point contact) % Fcxlf: Longitudinal creep force on left wheel flange contact patch (for two-point contact) % Fcyl: Lateral creep force on left wheel contact patch (for single-point contact) % Fcylt: Lateral creep force on left wheel tread contact patch (for two-point contact) % Fcylf: Lateral creep force on left wheel flange contact patch (for two-point contact) % Fczl: Vertical creep force on left wheel contact patch (for single-point contact) % Fczlt: Vertical creep force on left wheel tread contact patch (for two-point contact) % Fczlf: Vertical creep force on left wheel flange contact patch (for two-point contact) % Mcxl: Longitudinal creep moment on left wheel contact patch (for single-point contact) % Mcxlt: Longitudinal creep moment on left wheel tread contact patch (for two-point contact) % Mcxlf: Longitudinal creep moment on left wheel flange contact patch (for two-point contact) % Mcyl: Lateral creep moment on left wheel contact patch (for single-point contact) % Mcylt: Lateral creep moment on left wheel tread contact patch (for two-point contact) % Mcylf: Lateral creep moment on left wheel flange contact patch (for two-point contact) % Mczl: Vertical creep moment on left wheel contact patch (for single-point contact) % Mczlt: Vertical creep moment on left wheel tread contact patch (for two-point contact) % Mczlf: Vertical creep moment on left wheel flange contact patch (for two-point contact) % Fcxr: Longitudinal creep force on right wheel contact patch (for single-point contact) % Fcxrt: Longitudinal creep force on right wheel tread contact patch (for two-point contact) % Fcxrf: Longitudinal creep force on right wheel flange contact patch (for two-point contact) % Fcyr: Lateral creep force on right wheel contact patch (for single-point contact) % Fcyrt: Lateral creep force on right wheel tread contact patch (for two-point contact) % Fcyrf: Lateral creep force on right wheel flange contact patch (for two-point contact) % Fczr: Vertical creep force on right wheel contact patch (for single-point contact) % Fczrt: Vertical creep force on right wheel tread contact patch (for two-point contact) % Fczrf: Vertical creep force on right wheel flange contact patch (for two-point contact) % Mcxr: