MAP2: Model- and Acceleration-Based Pursuit with MPC and Gaussian Process Residual Learning for Autonomous Racing
Organizations: Zhejiang University · Center for Project-Based Learning, D-ITET, ETH Zurich
Abstract
Autonomous racing requires accurate trajectory tracking near the handling limits of a vehicle while maintaining low computational latency. Geometric controllers are computationally efficient, but the Ackermann steering geometry becomes invalid under limit-handling conditions. Model- and Acceleration-based Pursuit (MAP) preserves the simplicity of geometric approaches while leveraging tire dynamics. Yet MAP remains fundamentally a geometric controller that relies on Ackermann steering geometry, and its tire model may not fully capture the vehicle's actual dynamic response. This paper presents MAP2, a model-based pursuit controller that combines a curvature-based kinematic MPC and a Sparse Gaussian Process (SGP) residual correction. The proposed algorithm uses MPC to optimize kinematic control inputs over a prediction horizon and maps them to steering commands through a tire dynamics model augmented with SGP residual correction. Real-world vehicle experiments demonstrate substantial reductions in lateral tracking error and lap time. Compared with MAP and Pure Pursuit (PP), MAP2 reduces the average lateral tracking error by 37.99% and 44.65%, respectively, while reducing average lap time by at least 1.5%.
Figures & tables
| Controller | Compute | High-speed tracking | Model sensitivity |
| Pure Pursuit (PP) | Low | Limited | Low |
| MPC/MPCC | High | High | High |
| MAP | Low | Improved | High |
| MAP2 (ours) | Medium | High | Low |
| Parameters | Value | Parameters | Value |
| kg | |||
| kg m 2 | |||
| m | |||
| m | |||
| Parameters | Value | Parameters | Value |
| Velocity scale (%) | Controller | Avg. Lateral error (m) | Max. Lateral error (m) | Lap time (s) | ||||
| Avg. | Std. | Avg. | Std. | Fastest | Avg. | Std. | ||
| 50 | PP | 0.0298 | 0.0007 | 0.1035 | 0.0085 | 11.054 | 11.097 | 0.021 |
| MAP | 0.0325 | 0.0018 | 0.0851 | 0.0030 | 10.946 | 10.981 | 0.034 | |
| MAP2 w/o SGP | 0.0471 | 0.0022 | 0.1076 | 0.0078 | 11.070 | 11.121 | 0.034 | |
| MAP2 w/ SGP | 0.0504 | 0.0028 | 0.1190 | 0.0087 | 10.942 | 10.997 | 0.031 | |
| 60 | PP | 0.0723 | 0.0015 | 0.2100 | 0.0171 | 9.582 | 9.600 | 0.014 |
| Velocity scale (%) | Controller | Avg. Lateral error (m) | Max. Lateral error (m) | Lap time (s) | ||||
| Avg. | Std. | Avg. | Std. | Fastest | Avg. | Std. | ||
| 50 | PP | 0.0466 | 0.0013 | 0.1655 | 0.0063 | 8.146 | 8.172 | 0.018 |
| MAP | 0.0243 | 0.0008 | 0.1140 | 0.0063 | 8.054 | 8.080 | 0.019 | |
| MAP2 w/o SGP | 0.0503 | 0.0022 | 0.1088 | 0.0064 | 8.159 | 8.203 | 0.032 | |
| MAP2 w/ SGP | 0.0371 | 0.0018 | 0.1056 | 0.0097 | 8.047 | 8.099 | 0.038 | |
| 60 | PP | 0.1327 | 0.0029 | 0.3584 | 0.0160 | 7.031 | 7.087 | 0.033 |