Public Member Functions | Private Member Functions | Private Attributes
StopLine Class Reference

#include <stop_line.h>

Inheritance diagram for StopLine:
Inheritance graph

List of all members.

Public Member Functions

result_t control (pilot_command_t &pcmd, float topspeed=3.0)
void reset (void)
 StopLine (Navigator *navptr, int _verbose)
 ~StopLine ()

Private Member Functions

void reset_me (void)

Private Attributes

bool creeping
double initial_speed
double max_creep_distance
bool stopping

Detailed Description

Definition at line 15 of file stop_line.h.

Constructor & Destructor Documentation

StopLine::StopLine ( Navigator navptr,
int  _verbose 

This is based on the unpublished "Control Tutorial" draft dated January 26, 2004 by Dr. Benjamin Kuypers, section 5: "The Stopping Controller". He recommends a constant deceleration instead of the simpler exponential decay. The dynamical system is:

x_dot = -k * sqrt(x)

Solving analytically with initial condition x(0) = D and v(0) = V yields these equations of motion:

x(t) = (sqrt(D) - V*t/(2*sqrt(D)))**2 (parabolic drop) v(t) = dx/dt = (V**2/2*D)*t + V (linear velocity) a(t) = dv/dt = V**2/(2*D) = A (constant deceleration)

Note that the initial velocity V is negative in these equations, because it represents motion from positive x to zero. The system stops in finite time T = -2*D/V, with x(T) = 0, and v(T) = 0.

For example, when D = 10m from stop line and V = -5m/s, the vehicle stops in 4 seconds at a constant 1.25m/s/s deceleration.

Definition at line 42 of file

Definition at line 48 of file

Member Function Documentation

Controller::result_t StopLine::control ( pilot_command_t pcmd,
float  topspeed = 3.0 

Set speed for steady deceleration to stop way-point

course->stop_waypt is goal way-point of stop
pcmdcontains desired heading and speed, assuming it is not yet time to stop, updated on exit
topspeedvelocity limit
resets course-> if reached.
OK if in process of stopping; Finished if stop way-point reached.

Definition at line 63 of file

void StopLine::reset ( void  ) [virtual]

Reimplemented from Controller.

Definition at line 156 of file

void StopLine::reset_me ( void  ) [private, virtual]

Reimplemented from Controller.

Definition at line 163 of file

Member Data Documentation

Definition at line 28 of file stop_line.h.

double StopLine::initial_speed [private]

Definition at line 29 of file stop_line.h.

double StopLine::max_creep_distance [private]

Definition at line 30 of file stop_line.h.

Definition at line 27 of file stop_line.h.

The documentation for this class was generated from the following files:

Author(s): Austin Robot Technology, Jack O'Quin
autogenerated on Fri Jan 3 2014 11:08:43