quadratic_calculator.cpp
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2013, Willow Garage, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * * Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * * Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * * Neither the name of the Willow Garage, Inc. nor the names of its
14  * contributors may be used to endorse or promote products derived from
15  * this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
31 
32 namespace global_planner {
33 float QuadraticCalculator::calculatePotential(float* potential, unsigned char cost, int n, float prev_potential) {
34  // get neighbors
35  float u, d, l, r;
36  l = potential[n - 1];
37  r = potential[n + 1];
38  u = potential[n - nx_];
39  d = potential[n + nx_];
40  // ROS_INFO("[Update] c: %f l: %f r: %f u: %f d: %f\n",
41  // potential[n], l, r, u, d);
42  // ROS_INFO("[Update] cost: %d\n", costs[n]);
43 
44  // find lowest, and its lowest neighbor
45  float ta, tc;
46  if (l < r)
47  tc = l;
48  else
49  tc = r;
50  if (u < d)
51  ta = u;
52  else
53  ta = d;
54 
55  float hf = cost; // traversability factor
56  float dc = tc - ta; // relative cost between ta,tc
57  if (dc < 0) // tc is lowest
58  {
59  dc = -dc;
60  ta = tc;
61  }
62 
63  // calculate new potential
64  if (dc >= hf) // if too large, use ta-only update
65  return ta + hf;
66  else // two-neighbor interpolation update
67  {
68  // use quadratic approximation
69  // might speed this up through table lookup, but still have to
70  // do the divide
71  float d = dc / hf;
72  float v = -0.2301 * d * d + 0.5307 * d + 0.7040;
73  return ta + hf * v;
74  }
75 }
76 }
77 
d
float calculatePotential(float *potential, unsigned char cost, int n, float prev_potential)


global_planner
Author(s): David Lu!!
autogenerated on Thu Mar 12 2020 04:10:23