George's Submission

main.cc

@@ -5,10 +5,16 @@ int main() {
   Profile::ProfilePoint current;
   Profile::ProfilePoint goal;
   {
+  	// Position (distance) of 'goal'
     goal.position = 1.0;
+    // Velocity at 'goal'
     goal.velocity = 0.0;
   }
+
   Profile profile(current);
   profile.SetGoal(goal);
-  std::cout << profile.GetTime() << std::endl;
+
+  // TRUE = will calculate using maximum velocity; FALSE = won't calculate using maximum velocity
+  bool use_max_velocity = true;
+  std::cout << profile.GetTime(current, goal, use_max_velocity) << std::endl;
 }

profile.cc

@@ -1,5 +1,47 @@
 #include "profile.h"
+#include <cmath>
+#include <iostream>
 
-const double Profile::GetTime() {
-  return 0.0;
+// NOTE - This is a very rough draft, and not a finished product. These are just some of the calculations I will be using
+const double Profile::GetTime(ProfilePoint current, ProfilePoint goal, bool use_max_velocity) {
+	// 'a' = acceleration
+	double a = kMaxAcceleration;
+
+	// 't' = time
+	double t_accelerating;
+	double t_decelerating;
+	double t_constant_velocity;
+	double t_total;
+
+	// 'd' = distance
+	double d_accelerating;
+	double d_constant_velocity;
+	double d_decelerating;
+
+	// 'v' = velocity
+	double v_initial = current.velocity;
+	double v_max = kMaxVelocity;
+	double v_goal = goal.velocity;
+
+	// 'p' = position
+	double p_beginning = current.position;
+	double p_goal = goal.position;
+
+	if (use_max_velocity) {
+		// Time to reach the goal respecting ending at 0 velocity and `kMaxVelocity` and `kMaxAcceleration`
+		t_accelerating = std::abs(v_max-v_initial) / a;
+		t_decelerating = std::abs(v_goal-v_max) / a;
+
+		d_accelerating = 0.5 * std::abs(v_max + v_initial) * t_accelerating;
+		d_decelerating = 0.5 * std::abs(v_goal - v_max) * t_decelerating;
+
+		d_constant_velocity = p_goal - d_accelerating - d_decelerating;
+		t_constant_velocity = d_constant_velocity / v_max;
+
+		t_total = t_accelerating + t_constant_velocity + t_decelerating;
+	} else {
+		t_total = (-v_initial + std::sqrt(std::pow(v_initial, 2) + (4 * .5 * a * goal.position))) / a;
+	}
+
+	return t_total;
 }

profile.h

@@ -1,20 +1,25 @@
 #ifndef PROFILE_H_
 #define PROFILE_H_
 
-constexpr kMaxVelocity = 1.0;
-constexpr kMaxAcceleration = 1.0;
+constexpr double kMaxVelocity = 1.0;
+constexpr double kMaxAcceleration = 1.0;
 
 class Profile {
 public:
   struct ProfilePoint {
     double position = 0.0;
     double velocity = 0.0;
   };
+
   Profile(ProfilePoint current) {
     current_ = current;
   }
-  void SetGoal(ProfilePoint goal) { goal_ = goal; }
-  const double GetTime();
+
+  void SetGoal(ProfilePoint goal) { 
+    goal_ = goal; 
+  }
+
+  const double GetTime(ProfilePoint current, ProfilePoint goal, bool use_max_velocity);
 
 private:
   ProfilePoint current_;