A Neuro-Inspired Spike-Based PID Motor Controller for Multi-Motor Robots with Low Cost FPGAs

In this paper we present a neuro-inspired spike-based close-loop controller written in VHDL and implemented for FPGAs. This controller has been focused on controlling a DC motor speed, but only using spikes for information representation, processing and DC motor driving. It could be applied to other motors with proper driver adaptation. This controller architecture represents one of the latest layers in a Spiking Neural Network (SNN), which implements a bridge between robotics actuators and spike-based processing layers and sensors. The presented control system fuses actuation and sensors information as spikes streams, processing these spikes in hard real-time, implementing a massively parallel information processing system, through specialized spike-based circuits. This spike-based close-loop controller has been implemented into an AER platform, designed in our labs, that allows direct control of DC motors: the AER-Robot. Experimental results evidence the viability of the implementation of spike-based controllers, and hardware synthesis denotes low hardware requirements that allow replicating this controller in a high number of parallel controllers working together to allow a real-time robot control

A short curriculum of the robotics and technology of computer lab

Our research Lab is directed by Prof. Anton Civit. It is an interdisciplinary group of 23 researchers that carry out their teaching and researching labor at the Escuela Politécnica Superior (Higher Polytechnic School) and the Escuela de Ingeniería Informática (Computer Engineering School). The main research fields are: a) Industrial and mobile Robotics, b) Neuro-inspired processing using electronic spikes, c) Embedded and real-time systems, d) Parallel and massive processing computer architecture, d) Information Technologies for rehabilitation, handicapped and elder people, e) Web accessibility and usability In this paper, the Lab history is presented and its main publications and research projects over the last few years are summarized.Nuestro grupo de investigación está liderado por el profesor Civit. Somos un grupo multidisciplinar de 23 investigadores que realizan su labor docente e investigadora en la Escuela Politécnica Superior y en Escuela de Ingeniería Informática. Las principales líneas de investigaciones son: a) Robótica industrial y móvil. b) Procesamiento neuro-inspirado basado en pulsos electrónicos. c) Sistemas empotrados y de tiempo real. d) Arquitecturas paralelas y de procesamiento masivo. e) Tecnología de la información aplicada a la discapacidad, rehabilitación y a las personas mayores. f) Usabilidad y accesibilidad Web. En este artículo se reseña la historia del grupo y se resumen las principales publicaciones y proyectos que ha conseguido en los últimos años

Case study: Bio-inspired self-adaptive strategy for spike-based PID controller

A key requirement for modern large scale neuromorphic systems is the ability to detect and diagnose faults and to explore self-correction strategies. In particular, to perform this under area-constraints which meet scalability requirements of large neuromorphic systems. A bio-inspired online fault detection and self-correction mechanism for neuro-inspired PID controllers is presented in this paper. This strategy employs a fault detection unit for online testing of the PID controller; uses a fault detection manager to perform the detection procedure across multiple controllers, and a controller selection mechanism to select an available fault-free controller to provide a corrective step in restoring system functionality. The novelty of the proposed work is that the fault detection method, using synapse models with excitatory and inhibitory responses, is applied to a robotic spike-based PID controller. The results are presented for robotic motor controllers and show that the proposed bioinspired self-detection and self-correction strategy can detect faults and re-allocate resources to restore the controller’s functionality. In particular, the case study demonstrates the compactness (~1.4% area overhead) of the fault detection mechanism for large scale robotic controllers.Ministerio de Economía y Competitividad TEC2012-37868-C04-0

Real-time motor rotation frequency detection with event-based visual and spike-based auditory AER sensory integration for FPGA

Multisensory integration is commonly used in various robotic areas to collect more environmental information using different and complementary types of sensors. Neuromorphic engineers mimics biological systems behavior to improve systems performance in solving engineering problems with low power consumption. This work presents a neuromorphic sensory integration scenario for measuring the rotation frequency of a motor using an AER DVS128 retina chip (Dynamic Vision Sensor) and a stereo auditory system on a FPGA completely event-based. Both of them transmit information with Address-Event-Representation (AER). This integration system uses a new AER monitor hardware interface, based on a Spartan-6 FPGA that allows two operational modes: real-time (up to 5 Mevps through USB2.0) and data logger mode (up to 20Mevps for 33.5Mev stored in onboard DDR RAM). The sensory integration allows reducing prediction error of the rotation speed of the motor since audio processing offers a concrete range of rpm, while DVS can be much more accurate.Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0

ED-Scorbot: A Robotic test-bed Framework for FPGA-based Neuromorphic systems

Neuromorphic engineering is a growing and promising discipline nowadays. Neuro-inspiration and brain understanding applied to solve engineering problems is boosting new architectures, solutions and products today. The biological brain and neural systems process information at relatively low speeds through small components, called neurons, and it is impressive how they connect each other to construct complex architectures to solve in a quasi-instantaneous way visual and audio processing tasks, object detection and tracking, target approximation, grasping…, etc., with very low power. Neuromorphs are beginning to be very promising for a new era in the development of new sensors, processors, robots and software systems that mimic these biological systems. The event-driven Scorbot (EDScorbot) is a robotic arm plus a set of FPGA / microcontroller’s boards and a library of FPGA logic joined in a completely event-based framework (spike-based) from the sensors to the actuators. It is located in Seville (University of Seville) and can be used remotely. Spike-based commands, through neuro-inspired motor controllers, can be sent to the robot after visual processing object detection and tracking for grasping or manipulation, after complex visual and audio-visual sensory fusion, or after performing a learning task. Thanks to the cascade FPGA architecture through the Address-Event-Representation (AER) bus, supported by specialized boards, resources for algorithms implementation are not limited.Ministerio de Economía y Competitividad TEC2012-37868-C04-02Junta de Andalucía P12-TIC-130

An AER handshake-less modular infrastructure PCB with x8 2.5Gbps LVDS serial links

Nowadays spike-based brain processing emulation is taking off. Several EU and others worldwide projects are demonstrating this, like SpiNNaker, BrainScaleS, FACETS, or NeuroGrid. The larger the brain process emulation on silicon is, the higher the communication performance of the hosting platforms has to be. Many times the bottleneck of these system implementations is not on the performance inside a chip or a board, but in the communication between boards. This paper describes a novel modular Address-Event-Representation (AER) FPGA-based (Spartan6) infrastructure PCB (the AER-Node board) with 2.5Gbps LVDS high speed serial links over SATA cables that offers a peak performance of 32-bit 62.5Meps (Mega events per second) on board-to-board communications. The board allows back compatibility with parallel AER devices supporting up to x2 28-bit parallel data with asynchronous handshake. These boards also allow modular expansion functionality through several daughter boards. The paper is focused on describing in detail the LVDS serial interface and presenting its performance.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02/01Ministerio de Economía y Competitividad TEC2012-37868-C04-02/01Junta de Andalucía TIC-6091Ministerio de Economía y Competitividad PRI-PIMCHI-2011-076

A FPGA Spike-Based Robot Controlled with Neuro-inspired VITE

This paper presents a spike-based control system applied to a fixed robotic platform. Our aim is to take a step forward to a future complete spikes processing architecture, from vision to direct motor actuation. This paper covers the processing and actuation layer over an anthropomorphic robot. In this way, the processing layer uses the neuro-inspired VITE algorithm, for reaching a target, based on PFM taking advantage of spike system information: its frequency. Thus, all the blocks of the system are based on spikes. Each layer is implemented within a FPGA board and spikes communication is codified under the AER protocol. The results show an accurate behavior of the robotic platform with 6-bit resolution for a 130º range per joint, and an automatic speed control of the algorithm. Up to 96 motor controllers could be integrated in the same FPGA, allowing the positioning and object grasping by more complex anthropomorphic robots.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Ministerio de Economía y Competitividad TEC2012-37868-C04-0

Control neuromórfico del brazo robótico BIOROB del Citec de la Universidad de Bielefeld

Los sistemas neuronales biológicos responden a estímulos de una forma rápida y eficiente en el movimiento motor del cuerpo, comparado con los sistemas robóticos clásicos, los cuales requieren una capacidad de computación mucho más elevada. Una de las claves de estos sistemas es la codificación de la información en el dominio pulsante. Las neuronas se comunican por eventos con pequeños pulsos de corrientes producidas por intercambio de iones entre las dendritas y los axones de las mismas. La configuración en redes de neuronas permite no sólo el procesado de la información sensorial y su procesamiento en el dominio pulsante, sino también la propia actuación sobre los músculos en el formato pulsante. Este trabajo presenta la aplicación de un modelo de control motor basado en el procesado de pulsos, incluyendo la propia actuación sobre motores en el contexto de los pulsos. Se ha desarrollado un sistema de control en lazo cerrado por pulsos, denominado spikebased PID controller para FPGA, el cual se ha integrado en el esqueleto de un robot bioinspirado, BioRob X5 del CITEC de la Universidad de Bielefeld, para su uso en el desarrollo de modelos bioinspirados. El Robot, de más de 1m de largo, permite controlar las posiciones de las articulaciones usando control por pulsos y con un consumo menor de 1A para todos los grados de libertad funcionando al mismo tiempo.Compared to classic robotics, biological nervous systems respond to stimulus in a fast and efficient way regarding to the body motor movement. Classic robotic systems usually require higher computational capacity. One of the main keys of biological systems respect to robotic machines is the way the information is codded and transmitted. They use spikes. A neuron is the “basic” element that form biological nervous systems. Neurons communicate in an event-driven way through small current pulses (spikes) produced when ions are interchanged between dendrites and axons of different neurons. When neurons are arranged in networks, they allow not only the sensory information processing, but they also allow the actuation over the muscles in a spiking way. This paper presents the application of a motor control model based on spike processing, including the motor actuation in the spike domain. A close-loop control system, called spike-PID controller, has been developed for FPGA. This controller has been embedded into a bioinspired robot, called BioRob X5, at CITEC of the University of Bielefeld during a “Salvador de Madariaga” grant for a research visit in the july-september 2018 term. The robot, longer than 1 meter tall, allows the joint position control through spiking signals with a power consumption bellow 1A for the 4 DoF working at the same time.Ministerio de Educación y Ciencia (España)/FEDER. Proyecto COFNET TEC2016-77785-