Fig. 1.
Fig. 2.
Comparison of quality indicators obtained for DWA and the proposed PSDWA with different numer of examinations
| Quality indicator | DWA | PSDWA | ||
|---|---|---|---|---|
| Maximum number of examinations (itermax) | ||||
| 5 | 15 | 30 | ||
| Mean path length [m] | 6.23 | 7.03 | 6.19 | 6.18 |
| Mean smoothness [rad] | 1.063 | 1.253 | 1.059 | 1.056 |
| Mean goal-reaching time [s] | 12.60 | 14.57 | 12.58 | 12.56 |
| Speed-up | 1.00 | 5.31 | 1.93 | 0.92 |
Comparison of quality indicators obtained for DWA and the proposed PSDWA examined in a thousand randomly generated environments with ten obstacles
| Quality indicator | DWA | PSDWA |
|---|---|---|
| Mean path length [m] | 3.972 | 3.996 |
| Mean smoothness [rad] | 0.989 | 1.009 |
| Mean goal-reaching time [s] | 8.114 | 8.162 |
| Mean computation time of the algorithm [ms] | 22.97 | 11.60 |
| Speed-up | 1.00 | 1.98 |
Parameters of the examined local path planning algorithms
| Parameter | Symbol | Value |
|---|---|---|
| Sampling period | T_s | 0.01 s |
| Horizon of prediction | Hprediction | 1.0 s |
| Maximum linear acceleration | amax | 1.0 m/s2 |
| Maximum linear velocity | vmax | 0.5 m/s |
| Maximum angular acceleration | εmax | 1.0 · π rad/s2 |
| Maximum angular velocity | ωmax | 0.5 · π rad/s |
| Obstacle distance reaction | 2.0 | |
| DWA: number of samples for linear velocity | Nv | 3 |
| DWA: number of samples for angular velocity | Nω | 10 |
| PSDWA: maximum number of examinations | itermax | 15 |
| PSDWA: Initial step size | ΔInitial |
Comparison of computation time of algorithms for various obstacle density in the environment
| Number of obstacles | Mean computation time [ms] | Speedup | |
|---|---|---|---|
| DWA | PSDWA | ||
| 2 | 4.97 ± 1.49 | 2.68 ±0.81 | 1.85 |
| 6 | 13.26 ±3.77 | 6.76 ± 1.93 | 1.97 |
| 10 | 22.97 ±4.67 | 11.60 ± 3.59 | 1.98 |
| 15 | 42.92 ± 5.78 | 21.40 ±4.49 | 2.01 |
| 30 | 65.67 ± 7.12 | 33.07 ±5.13 | 1.99 |