Slip prediction using Hidden Markov models: Multidimensional sensor data to symbolic temporal pattern learning

We present experiments on the application of machine learning to predicting slip. The sensing information is provided by a force/torque sensor and an artificial finger, which has randomly distributed strain gauges and polyvinylidene fluoride (PVDF) films embedded in silicone resulting in multidimensional time-series data on the finger-object contact. An incipient slip is detected by studying temporal patterns in the data. The data is analysed using probabilistic clustering that transforms the data into a sequence of symbols, which is used to train a hidden Markov model (HMM) classifier. Experimental results show that the classifier can predict a slip, at least 100ms before a slip takes place, with an accuracy of 96% on the validation set.