Figure 1: Photorealistic picture of the control card. According to the electronics and hardware nstitute of Technology in 2 Hirose (HiBot Company, 20 robot controller such as: TI UART interfaces, also its Tech M4 Controller and he TITech M4 Controller. 7 based on the STM controller 32-bit ARM Cortex M4 at 168 MHz, it has LAN Ethemet, Can, SPI, I2C and /O, A/D at 12 bits, D/A and 9axis motions sensor. Fven USB and micro SD memory reader are available. On the other hand, this project developed features of Hibot company created at the Tokyo 004 by Professor Shigeo 8), has developed some The last one is designed features include Digita an electronic system and control to manipulate a snake like robot with continues redundant active modules. The electronic cards implemented are pre- set as a master-slave con roller that executes the joints control of each mechanical module. The figure 1 showing the main cards composed by one DSPic30F4011 microc hip with 16-bit microcontroller that incorporates the essential communication protocol of CAN, PWM outputs for motor control, analogue and digital ports; as well as a socket to connect to an external device through the UART. The aim of this project is to propose the basics with a low cost with different approaches for design of a snake like robot bio mimetically inspired with Figure 3: Kinds of snake locomotion. (Micu, 2018). There are different types of locomotion in snakes based on the condition of the terrain and the type of environment. In the development of the project the cards and control can reproduce any of the 4 forms types of snake’s locomotion presented in figure 3, however, the applications of the control system and the communications of the cards focused the serpentine locomotion, as verification of control system. (Rollinson, 2014). Figure 2: Conceptual design of modular snake like robot. passive wheel and similar hardware developed by HiBot. This paper intended to presents the design criteria for electronic system to control and manipulate the robots, in addition presents mathematical model analysis and simulation. Table 2: Microcontroller parameters. Table 1: Step-down voltage regulator. 3.2. Microcontroller 4.1 Serpenoidal Curves Analysis Progression of Electronic and Communication System for Motion Control of Modular Snake-like-Robot The following equations express the serpenoid curves proposed by Hirose. The length of the segment along the serpent is represented by S; a, b and c are parameters that determine the shape of the curve. o represents the position of the curve, a specifies undulation, b periods and c the angular speed. Figure 5: Master-Slave card developed. The figure 5 showing the real electronic card implemented in each mechanical module of the robot structure. This card execute the master or slave control condition; the result is been done with a single card design allows to be configured as a master or slave according to the needs. Each card is As a result: 1, is the number of the joint, that is, the first joint will have an equation with i = 1, the second with i = 2 and so on. Figure 6: Block diagram of the electronic card. Figure 8: Top: Articular angles with respect to time: a=- pi/4, c=pi/2, w=2pi*(0.5); Bottom: Articular angles with respect to time: a=pi/2, c=pi/2, w=2pi*(0.5). Figure 7: Simulation of trajectories behaviour and locomotion of the modular snake-type robot. The control and communication system of the developed card is presented in figure 6; this shows the diagram of any device with 5V supply voltage and logic, such as RF, Bluetooth, wifi modules that support the TTL/UART interface. The diagram also showing the following the communication protocols: CAN; UART, I2C that allow controlling any device such as sensors, servomotors, LEDs, etc. all them that support at the same time by the interface. The simulation includes the implementation of the joint trajectories in the mechanical modules of the robot. As a result, the robot design has been taken to the URDF format compatible by the RVIZ simulator and through the publisher and subscriber of ROS. The described angles previously and the equations produce the simulated trajectories on RVIZ. (Sanfilippo, 2017; Stavdahl, 2017). Figure 9: Result of robot simulation developing serpenoid curve in RVIZ-ROS. CAN communications were well executed by the controllers, which were the aim of this preliminary research. Figure 10: Motion sequence of robot like snake.
