Apparatus and methods for training path navigation by robots

Abstract

An apparatus and methods for training and/or operating a robotic device to follow a trajectory. A robotic vehicle may utilize a camera and stores the sequence of images of a visual scene seen when following a trajectory during training in an ordered buffer. Motor commands associated with a given image may be stored. During autonomous operation, an acquired image may be compared with one or more images from the training buffer in order to determine the most likely match. An evaluation may be performed in order to determine if the image may correspond to a shifted (e.g., left/right) version of a stored image as previously observed. If the new image is shifted left, right turn command may be issued. If the new image is shifted right then left turn command may be issued.

What is claimed is: 
     
         1 . A method of determining a control signal for a robot, the method being performed by a special purpose computing platform having one or more processors executing instructions stored by a non-transitory computer-readable storage medium, the method comprising:
 receiving first input features of a first type and second input features of a second type;   determining a subset of features by randomly selecting at least one of the first input features and at least one of the second input features;   comparing individual features of the subset to corresponding features of a plurality of training feature sets, individual ones of the plurality of training feature sets comprising a number of training features, the number being equal to or greater than the quantity of features within the subset of features;   based on the comparison, determining a similarity measure for a given training set of the plurality of training feature sets, the similarity measure characterizing similarity between features of the subset and features of the given training set;   responsive to the similarity measure breaching a threshold, selecting one or more training sets from the plurality of training sets;   determining one or more potential control signals for the robot, individual ones of the one or more potential control signals being associated with a corresponding training set of the plurality of training sets; and   determining the control signal based on a transformation obtained from the one or more potential control signals;   wherein:
 individual ones of the plurality of training feature sets comprise features of the first type and at least one feature of the second type; 
 individual ones of the plurality of training feature sets are obtained during training operation of the robot, the training operation being performed responsive to receiving a training signal from the robot; and 
 individual ones of the one or more potential control signals being determined based on the training signal and the features of the given training set. 
   
     
     
         2 . The method of  claim 1 , wherein the similarity measure is determined based on a difference between values of the features of the subset and values of the features of the given training set. 
     
     
         3 . The method of  claim 1 , wherein the similarity measure is determined based on a distance metric between individual features of the subset of features and corresponding features of the given training set. 
     
     
         4 . The method of  claim 3 , wherein selecting one or more training sets comprises selecting a training set associated with a smallest distance metric. 
     
     
         5 . The method of  claim 3 , wherein selecting one or more training sets comprises selecting N training sets associated with a lowest percentile of the distance metric, N being greater than two. 
     
     
         6 . The method of  claim 5 , wherein the transformation comprises a statistical operation performed on individual ones of the one or more potential control signals associated with the selected N training sets. 
     
     
         7 . The method of  claim 6 , wherein the statistical operation is selected from the group including mean and percentile. 
     
     
         8 . The method of  claim 5 , wherein the transformation comprises a weighted sum of a product of individual ones of the one or more potential control signals and a corresponding distance measure associated with the selected N training sets. 
     
     
         9 . The method of  claim 1 , wherein:
 the control signal is configured to cause the robot to execute the action;   the first input type comprises a digital image comprising a plurality of pixel values; and   the second input type comprises a binary indication associated with the action being executed.   
     
     
         10 . The method of  claim 9 , wherein:
 the training comprises a plurality of iterations configured based on the training signal; and   a given iteration is characterized by a control command and a performance measure associated with the action execution based on the control command.   
     
     
         11 . The method of  claim 9 , wherein:
 the plurality of pixels comprises at least 10 pixels; and   the random selection is performed based on a random number generation operation.   
     
     
         12 . A self-contained robotic apparatus, the apparatus comprising:
 a platform comprising a motor;   a first sensor component configured to provide a signal conveying a video frame comprising a plurality of pixels;   a second sensor component configured to provide a binary sensor signal characterized by one of two states;   a memory component configured to store training sets, a given training set comprising an instance of the video frame, an instance of the binary signal, and an instance of a motor control indication configured to cause the robot to execute an action; and   one or more physical processors configured to operate a random k-nearest neighbors learning process to determine a motor control indication by at least:
 determining a subset of features comprising the binary signal and a set of pixels randomly selected from the plurality of pixels; 
 scaling individual pixels of the set of pixels by a scaling factor; 
 scaling features of the subset by a scaling factor; 
 comparing individual scaled features of the subset to corresponding features of individual ones of the training sets; 
 based on the comparison, determining a similarity measure for a given training set, the similarity measure characterizing similarity between features of the subset and features of the given training set; 
 based on an evaluation of the similarity measure, selecting one or more of the training sets; 
 determining one or more potential control signals for the robot, individual ones of the one or more potential control signals being associated with a corresponding training set; and 
 determining the control signal based on a transformation obtained from the one or more potential control signals; 
   wherein:
 individual ones of the plurality of training feature sets comprise features of the first type and at least one feature of the second type; 
 individual ones of the plurality of training feature sets are obtained during training operation of the robot, the training operation being performed responsive to receiving a training signal from the robot; and 
 individual ones of the one or more potential control signals being determined based on the training signal and the features of the given training set. 
   
     
     
         13 . The apparatus of  claim 12 , wherein:
 scaling comprises a multiplication of the first input by the scaling factor; and   the scaling factor is determined based on a number of pixels in the subset.   
     
     
         14 . The apparatus of  claim 13 , wherein the scaling factor is determined based on a ratio of a range of pixel values to a range of the binary values. 
     
     
         15 . The apparatus of  claim 12 , wherein:
 the action comprises target-approach-obstacle-avoidance; and   scaling is performed based on a size of obstacle or object as it appears in the video frame.   
     
     
         16 . The apparatus of  claim 12 , wherein scaling is a pixel specific. 
     
     
         17 . A non-transitory computer-readable storage medium having instructions embodied thereon, the instructions being executable by a processor to perform a method of selecting an outcome of a plurality of outcomes, the method comprising:
 determining a history of sensory input;   applying a transformation to an instance of the sensory input, the transformation being configured to produce scaled input based on analysis of the history;   determining a set of features comprising features of a first type randomly selected from the scaled input and at least one feature of a second type;   comparing individual features of the set to corresponding features of a plurality of training feature sets, individual ones of the plurality of training feature sets comprising a number of training features, the number being equal to or greater than the quantity of features within the set of features;   based on the comparison, determining a similarity measure for a given training set of the plurality of training feature sets, the similarity measure characterizing similarity between features of the subset and features of the given training set;   responsive to the similarity measure breaching a threshold, selecting one or more training sets from the plurality of training sets;   determining one or more potential control signals for the robot, individual ones of the one or more potential control signals being associated with a corresponding training set of the plurality of training sets; and   determining the control signal based on a transformation obtained from the one or more potential control signals;   wherein:
 individual ones of the plurality of training feature sets comprise features of the first type and at least one feature of the second type; 
 individual ones of the plurality of training feature sets are obtained during training operation of the robot, the training operation being performed responsive to receiving a training signal from the robot; and 
 individual ones of the one or more potential control signals being determined based on the training signal and the features of the given training set. 
   
     
     
         18 . The storage medium of  claim 17 , wherein:
 the analysis of the history comprises a determination of feature mean and feature standard deviation; and   the transformation comprises subtracting the feature mean and dividing the outcome by the feature standard deviation.   
     
     
         19 . The storage medium of  claim 17 , wherein:
 the set comprises a plurality of set features, individual ones of the set features characterized by a pointer; and   the feature mean and the feature standard deviation is configured for a respective pointer.   
     
     
         20 . The storage medium of  claim 19 , wherein:
 the input of the first type comprises a matrix of values;   the pointer identifies a value within the matrix; and   the feature mean and the feature standard deviation are configured for a given location within the matrix.