gyrodometry sensor fusion

common/mb_odometry.c

@@ -8,7 +8,8 @@
 #include "../mobilebot/mobilebot.h"
 #include "mb_defs.h"
 #include <math.h>
-
+#include <stdlib.h>
+typedef enum { F, T } boolean;
 #define PI 3.14159265358979323846
 //float enc2meters = (WHEEL_DIAMETER * PI) / (GEAR_RATIO * ENCODER_RES);
 /*******************************************************************************
@@ -35,7 +36,12 @@ void mb_initialize_odometry(mb_odometry_t* mb_odometry, float x, float y, float
 void mb_update_odometry(mb_odometry_t* mb_odometry, mb_state_t* mb_state){
     // mb_odometry is the input of previenc2metersous veh's position and orientation
     // Reference: https://www.hmc.edu/lair/ARW/ARW-Lecture01-Odometry.pdf  P28
+    //del_thresh Needs to be tuned
+    //IF DON'T WANT GYRO, SET IT AS F!
     float enc2meters = (WHEEL_DIAMETER * PI) / (GEAR_RATIO * ENCODER_RES);
+    float del_thesh = 0.125/DT; 
+    boolean Gyro = T;
+
     float del_left = mb_state->left_encoder_delta * 1.0 * enc2meters;
     float del_right = mb_state->right_encoder_delta * 1.0 * enc2meters;
     float del_s = (del_right - del_left) / 2;//float del_s = (del_left + del_right) / 2;
@@ -44,8 +50,19 @@ void mb_update_odometry(mb_odometry_t* mb_odometry, mb_state_t* mb_state){
     float del_y = del_s * sin(mb_odometry->theta + del_theta/2);
     mb_odometry->x += del_x;
     mb_odometry->y += del_y;
-    mb_odometry->theta += del_theta;
-    mb_odometry->theta = mb_clamp_radians(mb_odometry->theta);
+
+
+    // Gyro: we only need to use yaw
+    // Since each time step is small, no need to integrate
+    float del_theta_gyro = mb_state->gyro[2] * (PI / 180.0) * DT;
+    float del_go = del_theta_gyro - del_theta;
+    if (Gyro == T){
+        if (abs(del_go) > del_thesh){mb_odometry->theta += del_theta_gyro * DT;}
+        else{mb_odometry->theta += del_theta * DT;}
+    }
+    else{// this is after we update the del_x and y 
+        mb_odometry->theta += del_theta;}
+    mb_odometry->theta = mb_clamp_radians(mb_odometry->theta); 
 }