Development of an Autonomous Hexapod Robot with Digital Image Processing Implemented on Raspberry Pi

Rodrigo Barbosa Letang¹; Ricardo Naoki Mori¹; Alexandre Brincalepe Campo¹

¹ Instituto Federal de São Paulo

doi:10.20906/CPS/COB-2015-0511

Resumo

Currently many of robotic systems are developed with some kind of inspiration in nature, seeking to get flexibility and the efficiency of biological systems. An example are the hexapod robots, six-legged robots which movements try to imitate the movements of the insects, walking with two groups of three legs alternately, providing stability to the robot, flexibility in movement and better mobility on irregular surfaces. With these attributes the hexapod robots can be used in exploration of irregular terrains, inhospitable places or places with difficult access to humans. This project involves the development in an embedded system of an autonomous hexapod robot (Beetle-I) with digital image processing implemented on Raspberry Pi, to studies in the areas of autonomous robotic systems with legged locomotion and robotic vision. The robot has three degrees of freedom in each one of the six legs, is equipped with a camera to capture images and also uses a distance sensor that allow the robot to detect obstacles. The movements of each "leg" of the robot are performed by calculating the inverse kinematics for each point of a discretised trajectory, determining the angles required in each joint axes, which in turn is converted into PWM control signal for servomotors. This control was implemented in a Digital Signal Controller (DSC), a hybrid that combines the functionalities of a microcontroller with the processing capacity of a Digital Signal Processor (DSP). The Hexapod Robot Beetle-I is able to recognize the presence of a tennis ball on a neutral scenario, where doesn't occurs the object camouflage. The image processing and the distance detection was implemented on a Raspberry Pi, an integrated computer on a single board with a Raspbian Linux system. It was also planned a connection between the Raspberry Pi and the Digital Signal Controller (DSC) to enable a future implementation of a robot navigation control on the Raspberry Pi.

Palavras-chave: hexapod robot; digital image processing; Raspberry Pi; inverse kinematics; DSC