Uploaded May 2018 | Updated September 2026, 2 weeks ago
ICRA 2018 Spotlight Video
Interactive Session Tue PM Pod T.4
Authors: Koert, Dorothea; Maeda, Guilherme Jorge; Neumann, Gerhard; Peters, Jan
Title: Learning Coupled Forward-Inverse Models with Combined Prediction Errors
Abstract:
Challenging tasks in unstructured environments require robots to learn complex models. Given a large amount of information, learning multiple simple models can offer an efficient alternative to a monolithic complex network. Training multiple models---that is, learning their parameters and their responsibilities---has been shown to be prohibitively hard as optimization is prone to local minima. To efficiently learn multiple models for different contexts, we thus develop a new algorithm based on expectation maximization (EM). In contrast to comparable concepts, this algorithm trains multiple modules of paired forward-inverse models by using the prediction errors of both forward and inverse models simultaneously. In particular, we show that our method yields a substantial improvement over only considering the errors of the forward models on tasks where the inverse space contains multiple solutions.
ICRA 2018 Spotlight Video
Interactive Session Tue PM Pod T.4
Authors: Koert, Dorothea; Maeda, Guilherme Jorge; Neumann, Gerhard; Peters, Jan
Title: Learning Coupled Forward-Inverse Models with Combined Prediction Errors
Abstract:
Challenging tasks in unstructured environments require robots to learn complex models. Given a large amount of information, learning multiple simple models can offer an efficient alternative to a monolithic complex network. Training multiple models---that is, learning their parameters and their responsibilities---has been shown to be prohibitively hard as optimization is prone to local minima. To efficiently learn multiple models for different contexts, we thus develop a new algorithm based on expectation maximization (EM). In contrast to comparable concepts, this algorithm trains multiple modules of paired forward-inverse models by using the prediction errors of both forward and inverse models simultaneously. In particular, we show that our method yields a substantial improvement over only considering the errors of the forward models on tasks where the inverse space contains multiple solutions.



![Learning to Parse Natural Language to Grounded Reward Functions with Weak Supervision
ICRA 2018 Spotlight Video
Interactive Session Wed PM Pod I.1
Authors: Williams, Edward; Gopalan, Nakul; Rhee, Mina; Tellex, Stefanie
Title: Learning to Parse Natural Language to Grounded Reward Functions with Weak Supervision
Abstract:
In order to intuitively and efficiently collaborate with humans, robots must learn to complete tasks specified using natural language. We represent natural language instructions as goal-state reward functions specified using lambda calculus. Using reward functions as language representations allows robots to plan efficiently in stochastic environments. To map sentences to such reward functions, we learn a weighted linear Combinatory Categorial Grammar (CCG) semantic parser. The parser, including both parameters and the CCG lexicon, is learned from a validation procedure that does not require execution of a planner, annotating reward functions, or labeling parse trees, unlike prior approaches. To learn a CCG lexicon and parse weights, we use coarse lexical generation and validation-driven perceptron weight updates using the approach of Artzi and Zettlemoyer [4]. We present results on the Cleanup World domain [19] to demonstrate the potential of our approach. We report an F1 score of 0.82 on a collected corpus of 23 tasks containing combinations of nested referential expressions, comparators and object properties with 2037 corresponding sentences. Our goal-condition learning approach enables an improvement of orders of magnitude in computation time over a baseline that performs planning during learning, while achieving comparable results. Further, we conduct an experiment with just 6 labeled demonstrations to show the ease of teaching a robot behaviors using our method. Learning to Parse Natural Language to Grounded Reward Functions with Weak Supervision](https://i.ytimg.com/vi/c9Up1R_jlew/mqdefault.jpg)






