IZU2020
pitot tube strain gauge
Dependencies: mbed ADS1015 SDFileSystem
Revision 0:cf0be1174e43, committed 2020-03-23
- Comitter:
- nakumur
- Date:
- Mon Mar 23 05:57:30 2020 +0000
- Commit message:
- a
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ADS1015.lib Mon Mar 23 05:57:30 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/teams/PQ_Hybrid_Electrical_Equipment_Team/code/ADS1015/#71b44421e736
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/SDFileSystem.lib Mon Mar 23 05:57:30 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/teams/IZU2020/code/SDFileSystem/#93a0ff656a86
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Mon Mar 23 05:57:30 2020 +0000
@@ -0,0 +1,152 @@
+#include "mbed.h"
+#include "Adafruit_ADS1015.h"
+#include "SDFileSystem.h"
+#define ADS1115_ADDR 0b1001000
+
+Serial pc(USBTX, USBRX, 115200);
+I2C i2c(p28, p27);
+Adafruit_ADS1115 ads1115(&i2c, ADS1115_ADDR);
+SDFileSystem sd_file_system(p5, p6, p7, p8, "sd");
+Timer sd_timer;
+
+FILE *sd;
+char file_name[64];
+char f_sd;
+int16_t val[4] = {};
+float voltage[4] = {};
+float sum[4] = {};
+float v_ave[4] = {};
+float strain_v[4] = {};
+
+int main()
+{
+ ads1115.setGain(GAIN_TWOTHIRDS);
+
+ char file_name_format[] = "/sd/IZU2020_MISSION_%d.dat";
+ int file_number = 1;
+ while(1) {
+ sprintf(file_name, file_name_format, file_number);
+ sd = fopen(file_name, "r");
+ if(sd != NULL) {
+ fclose(sd);
+ file_number++;
+ } else {
+ sprintf(file_name, "/sd/IZU2020_MISSION_%d.dat", file_number);
+ break;
+ }
+ }
+ sd = fopen(file_name, "w");
+ sd_timer.start();
+ if(sd) {
+ fprintf(sd, "f_sd, ");
+ fprintf(sd, "speed[m/s],");
+ fprintf(sd, "sigma1,");
+ fprintf(sd, "sigma2,");
+ fprintf(sd, "taumax[MPa],");
+ fprintf(sd, "\r\n");
+ }
+
+ for(int i = 0; i < 10; i ++ ) {
+ val[0] = ads1115.readADC_SingleEnded(0);
+ val[1] = ads1115.readADC_SingleEnded(1);
+ val[2] = ads1115.readADC_SingleEnded(2);
+ val[3] = ads1115.readADC_SingleEnded(3);
+ voltage[0] = val[0] / 32768.0 * 6.144;
+ voltage[1] = val[1] / 32768.0 * 6.144;
+ voltage[2] = val[2] / 32768.0 * 6.144;
+ voltage[3] = val[3] / 32768.0 * 6.144;
+ sum[0] += voltage[0];
+ sum[1] += voltage[1];
+ sum[2] += voltage[2];
+ sum[3] += voltage[3];
+ }
+ v_ave[0] = sum[0] / 10.0;
+ v_ave[1] = sum[1] / 10.0;
+ v_ave[2] = sum[2] / 10.0;
+ v_ave[3] = sum[3] / 10.0;
+
+ while(1) {
+ val[0] = ads1115.readADC_SingleEnded(0);
+ val[1] = ads1115.readADC_SingleEnded(1);
+ val[2] = ads1115.readADC_SingleEnded(2);
+ val[3] = ads1115.readADC_SingleEnded(3);
+ voltage[0] = val[0] / 32768.0 * 6.144;
+ voltage[1] = val[1] / 32768.0 * 6.144;
+ voltage[2] = val[2] / 32768.0 * 6.144;
+ voltage[3] = val[3] / 32768.0 * 6.144;
+ pc.printf("%d, r%d, g%d, w%d\r\n", val[0], val[1], val[2], val[3]);
+ pc.printf("%f, r%f, g%f, w%f [V]\r\n", voltage[0], voltage[1], voltage[2], voltage[3]);
+
+ /*pitot_tube
+ -------------------------------------------------*/
+ float pitot_v = voltage[0] - v_ave[0] + 1;
+ //P = ((Vout / Vs) - 0.2) / 0.2
+ float pitot_Pa = (pitot_v / 5.0 - 0.2) / 0.2;
+ printf("pressure %f[kPa]\r\n", pitot_Pa);
+ float density = 1.3;
+ //v = root(2 * P / ρ)
+ float pitot_speed = sqrt(2 * pitot_Pa * 1000 / density);
+ printf("speed %f[m/s]\r\n", pitot_speed);
+ printf("speed %f[km/h]\r\n", pitot_speed * 3600 / 1000.0);
+
+ /*strain_gauge
+ ----------------------------------------------------*/
+ strain_v[1] = voltage[1] - v_ave[1];
+ strain_v[2] = voltage[2] - v_ave[2];
+ strain_v[3] = voltage[3] - v_ave[3];
+ //VOUT – VREF = G(VIN+ – VIN–)
+ //VREF = GND
+ //G = (49.4kΩ/RG) + 1
+ //straun = 2/3.3*V
+ float G = (49.4 * 1000 / 120.0) + 1;
+ float V1 = strain_v[1] / G;
+ float strain1 = 2 / 3.3 * V1 * 1000000.0;
+ float V2 = strain_v[2] / G;
+ float strain2 = 2 / 3.3 * V2 * 1000000.0;
+ float V3 = strain_v[3] / G;
+ float strain3 = 2 / 3.3 * V3 * 1000000.0;
+ printf("strain r %f g %f w %f [uε]\r\n", strain1, strain2, strain3);
+
+ float E = 2.5;//Al 72GPa
+ float nu = 0.3;//ポアソン比
+ float g = E / 2 / (1 + nu); //横弾性係数
+ float sigmax = E / (1 - nu * nu) * (strain1 + nu * strain3) / 1000.0;
+ float sigmay = E / (1 - nu * nu) * (nu * strain1 + strain3) / 1000.0;
+ float gammaxy = 2 * strain2 - strain1 - strain3;
+ float tauxy = g * gammaxy / 1000.0;
+ float sigma1 = (sigmax + sigmay) + sqrt((sigmax - sigmay) * (sigmax - sigmay) + 4 * tauxy * tauxy);
+ float sigma2 = (sigmax + sigmay) - sqrt((sigmax - sigmay) * (sigmax - sigmay) + 4 * tauxy * tauxy);
+ float taumax = (sigma1 - sigma2) / 2.0;
+ printf("sigmax %f sigmay %f tauxy %f [MPa]\r\n", sigmax, sigmay, tauxy);
+ printf("sigma1 %f sigma2 %f taumax %f [MPa]\r\n", sigma1, sigma2, taumax);
+
+ /*sd
+ --------------------------------------------------------*/
+ f_sd = bool(sd);
+ if(sd) {
+ fprintf(sd, "%d,", f_sd);
+ fprintf(sd, "%f,", pitot_speed);
+ fprintf(sd, "%f,", sigma1);
+ fprintf(sd, "%f,", sigma2);
+ fprintf(sd, "%f,", taumax);
+ fprintf(sd, "\r\n");
+ }
+ if(sd_timer.read_ms() >= 60*1000) {
+ sd_timer.reset();
+ sd_timer.start();
+ if(sd) {
+ fclose(sd);
+ sd = fopen(file_name, "a");
+ }
+ }
+
+ /*test
+ ----------------------------------------------------*/
+ float P = 5.0 * 9.8;
+ float A = 14.5 * 3.0;
+ float sigma = P / A;
+ pc.printf("test %f\r\n", sigma);
+
+ wait(0.5);
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Mon Mar 23 05:57:30 2020 +0000 @@ -0,0 +1,1 @@ +https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400 \ No newline at end of file