car.c

关于XD256的应用实例,用于汽车电子开发之用

/*****************************************************
 car.c - simulates the behavior of a car
 ----------------------------------------------------
 The function SimulateCar should be called in regular
 interval (100ms) 
 *****************************************************/

#include "hidef.h" /* this file declares symbols user by the CodeWarrior environment */

#include <stdlib.h>
#include <math.h>
#include "globals.h"
#include "car.h"

#define GEARS (sizeof(ratio) / sizeof(int))  /* number of gears (calculate elements of array below) */
#define SPEED_TACHO_RATIO   40

static float ratio[] = {1.2, 
               0.70,
               0.45,
               0.28,
               0.20};  /* gear ratios; one entry per gear */


static float E = 0;         // energy of the car ( (m * v^2) / 2 )
static int   m = 25;        // mass of the car
static float v;             // speed of the car
static float Cw = 0.20;     // wind resistance coefficient
static int   dE = 1000;	    // energy from the engine
static int   fBrake = 0;    // brake force
static float rpm = 0;	      // RPM of the motor
static float rollRes = 1;   // rolling resistance
static float Fule = 100;    // Fule tank
static float Temp = 0;      // temperature
static int   vi;
static int   rpmi;
static int   vTarget = 120;
static int   autoSpeed = 1;
static int   gear = 0;

#define MAX_E  1950


void  SimulateCar(void)
{
    float rpml, de, deLim, resistance;
    int i;
	
    if (fBrake > 5) {
      autoSpeed = 0;
      dE = 0;
    } else {
      fBrake = 0;
    }
    resistance = 10 * rollRes + rollRes * v + Cw * v * v * v / 1950;
    if (Fule > 0) {
      if (v < 250) {
        if (autoSpeed) {
          fBrake = 0;
          de = (vTarget - v) * 200 + resistance;
          if (de < 0) {            
            de = 0;
          } else {
            deLim = v * v / 20 + 500;
            if (de > deLim) { 
              de = deLim;
            }
            if (de > MAX_E) {
              de = MAX_E;
            }
          }
          dE = de;
         }
      } else {
        dE = dE * 0.995;
      }
      E = E + dE; 
      Temp = Temp + 0.03 * dE / MAX_E;
      Fule = Fule - 0.002 * dE / MAX_E;
    } 
    E = E - fBrake * v; // brake with constant force
    E = E - resistance;
    if (E < 0) {      
      E = 0;
    }
    if (Temp > 60) {
      Temp = Temp - 0.02; // cooler fan on
    }
    Temp = Temp - 0.001;

    v = sqrtf ( E / m * 2);
 	  i = 0;	
 		do {
 		   rpml = v * 90 * ratio[i];
 		   i++;
 		} while (rpml > (4500 - (MAX_E - dE) * 1.7) && i < 5);
 		if (rpml < 600) rpml = 600;
 		rpm = rpml;
 		
 		gear = i;
 		vi = v;
 		rpmi = rpm;
    
 		GDICData.SpeedPosition = (int)(v * 14);
 		GDICData.RPMPosition =   (int)(rpm * 0.53);
 		GDICData.FuelPosition =  (int)(Fule * 12 + 1000);
 		GDICData.CoolPosition =  (int)(Temp * 12 + 1000);
  
  
}