Analytical models for robot dynamics often perform suboptimally in practice, due to various non-linearities and the difficulty of accurately estimating the dynamic parameters. Machine learning techniques are less sensitive to these problems and therefore an interesting alternative for modeling robot dynamics. We propose a learning method that combines a least squares algorithm with a non-linear feature mapping and an efficient update rule. Using data from five different robots, we show that the method can accurately model manipulator dynamics, either when trained in batch or incrementally. Furthermore, the update time and memory usage of the method are bounded, therefore allowing use in real-time control loops.

One of the major challenges in developing autonomous systems is to make them able to recognize and categorize objects robustly. However, the appearance-based algorithms that are widely employed for robot perception do not explore the functionality of objects, described in terms of their affordances. These affordances (e.g., manipulation, grasping) are discriminative for object categories and are important cues for reliable robot performance in everyday environments. In this paper, we propose a strategy for object recognition that integrates both visual appearance and grasp affordance features. Following previous work, we hypothesize that additional grasp information improves object recognition, even if we reconstruct the grasp modality from visual features using a mapping function. We considered two different representations for the grasp modality: (1) motor information of the hand posture while grasping and (2) a more general grasp affordance descriptor. Using a multi-modal classifier we show that having real grasp information significantly boost object recognition. This improvement is preserved, although to a lesser extent, if the grasp modality is reconstructed using the mapping function.