Insect inspired visual motion sensing and flying robots

International audienceFlying insects excellently master visual motion sensing techniques. They use dedicated motion processing circuits at a low energy and computational costs. Thanks to observations obtained on insect visual guidance, we developed visual motion sensors and bio-inspired autopilots dedicated to flying robots. Optic flow-based visuomotor control systems have been implemented on an increasingly large number of sighted autonomous robots. In this chapter, we present how we designed and constructed local motion sensors and how we implemented bio-inspired visual guidance scheme on-board several micro-aerial vehicles. An hyperacurate sensor in which retinal micro-scanning movements are performed via a small piezo-bender actuator was mounted onto a miniature aerial robot. The OSCAR II robot is able to track a moving target accurately by exploiting the microscan-ning movement imposed to its eye's retina. We also present two interdependent control schemes driving the eye in robot angular position and the robot's body angular position with respect to a visual target but without any knowledge of the robot's orientation in the global frame. This "steering-by-gazing" control strategy, which is implemented on this lightweight (100 g) miniature sighted aerial robot, demonstrates the effectiveness of this biomimetic visual/inertial heading control strategy

Engineering Data Compendium. Human Perception and Performance, Volume 1

The concept underlying the Engineering Data Compendium was the product an R and D program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design of military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by system designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is Volume 1, which contains sections on Visual Acquisition of Information, Auditory Acquisition of Information, and Acquisition of Information by Other Senses

Data analysis of retinal recordings from multi-electrode arrays under in situ electrical stimulation

The development of retinal implants has become an important field of study in recent years, with increasing numbers of people falling victim to legal or physical blindness as a result of retinal damage. Important weaknesses in current retinal implants include a lack of the resolution necessary to give a patient a viable level of visual acuity, question marks over the amount of power and energy required to deliver adequate stimulation, and the removal of eye movements from the analysis of the visual scene. This thesis documents investigations by the author into a new CMOS stimulation and imaging chip with the potential to overcome these difficulties. An overview is given of the testing and characterisation of the componments incorporated in the device to mimic the normal functioning of the human retina. Its application to in situ experimental studies of frog retina is also described, as well as how the data gathered from these experiments enables the optimisation of the geometry of the electrode array through which the device will interface with the retina. Such optimisation is important as the deposit of excess electrical charge and energy can lead to detrimental medical side effects. Avoidance of such side effects is crucial to the realisation of the next generation of retinal implants

Design, Control, and Evaluation of a Human-Inspired Robotic Eye

Schulz S. Design, Control, and Evaluation of a Human-Inspired Robotic Eye. Bielefeld: Universität Bielefeld; 2020.The field of human-robot interaction deals with robotic systems that involve humans and robots closely interacting with each other. With these systems getting more complex, users can be easily overburdened by the operation and can fail to infer the internal state of the system or its ”intentions”. A social robot, replicating the human eye region with its familiar features and movement patterns, that are the result of years of evolution, can counter this. However, the replication of these patterns requires hard- and software that is able to compete with the human characteristics and performance. Comparing previous systems found in literature with the human capabili- ties reveal a mismatch in this regard. Even though individual systems solve single aspects, the successful combination into a complete system remains an open challenge. In contrast to previous work, this thesis targets to close this gap by viewing the system as a whole — optimizing the hard- and software, while focusing on the replication of the human model right from the beginning. This work ultimately provides a set of interlocking building blocks that, taken together, form a complete end-to-end solution for the de- sign, control, and evaluation of a human-inspired robotic eye. Based on the study of the human eye, the key driving factors are identified as the success- ful combination of aesthetic appeal, sensory capabilities, performance, and functionality. Two hardware prototypes, each based on a different actua- tion scheme, have been developed in this context. Furthermore, both hard- ware prototypes are evaluated against each other, a previous prototype, and the human by comparing objective numbers obtained by real-world mea- surements of the real hardware. In addition, a human-inspired and model- driven control framework is developed out, again, following the predefined criteria and requirements. The quality and human-likeness of the motion, generated by this model, is evaluated by means of a user study. This frame- work not only allows the replication of human-like motion on the specific eye prototype presented in this thesis, but also promotes the porting and adaption to less equipped humanoid robotic heads. Unlike previous systems found in literature, the presented approach provides a scaling and limiting function that allows intuitive adjustments of the control model, which can be used to reduce the requirements set on the target platform. Even though a reduction of the overall velocities and accelerations will result in a slower motion execution, the human characteristics and the overall composition of the interlocked motion patterns remain unchanged

Saccadic suppression by way of retinal image processing

Humans make eye movements such as saccades four times every second. Saccades disrupt the visual flow on the retina; however, visual perception remains a stable and coherent process. This is a striking achievement of the visual system. Visual stability around the time of these eye movements is partially associated with a reduction in visual sensitivity, a phenomenon known as saccadic suppression. While saccadic suppression has been extensively characterized at the perceptual and neural levels, its underlying mechanisms remain elusive. According to the favored view, eye-movement related signals play a central role in the genesis of saccadic suppression. Despite extensive efforts to substantiate these claims, the neural origin of such signals has not been established. In this dissertation, we challenge the dominant view that saccadic suppression is triggered by eye-movement related signals. Instead, using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics we show evidence that visual mechanisms starting at the retina account for perceptual saccadic suppression. Cellular and circuit level descriptions of these retinal mechanisms are presented in detail. Most notably, we find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. We also found that eye-movement related signals act to shorten the suppression resulting from visual mechanisms - a diametrically opposite involvement of eye movement signals than proposed in the literature. Overall, our results establish a neural locus of saccadic suppression, and provide detailed mechanistic insights underlying it. These findings resolve a long-standing open question concerning the origin of saccadic suppression. Given that the retinal saccadic suppression is triggered by sequential visual stimulation, our results also describe retinal processing of dynamic stimuli

Visual Cortex

The neurosciences have experienced tremendous and wonderful progress in many areas, and the spectrum encompassing the neurosciences is expansive. Suffice it to mention a few classical fields: electrophysiology, genetics, physics, computer sciences, and more recently, social and marketing neurosciences. Of course, this large growth resulted in the production of many books. Perhaps the visual system and the visual cortex were in the vanguard because most animals do not produce their own light and offer thus the invaluable advantage of allowing investigators to conduct experiments in full control of the stimulus. In addition, the fascinating evolution of scientific techniques, the immense productivity of recent research, and the ensuing literature make it virtually impossible to publish in a single volume all worthwhile work accomplished throughout the scientific world. The days when a single individual, as Diderot, could undertake the production of an encyclopedia are gone forever. Indeed most approaches to studying the nervous system are valid and neuroscientists produce an almost astronomical number of interesting data accompanied by extremely worthy hypotheses which in turn generate new ventures in search of brain functions. Yet, it is fully justified to make an encore and to publish a book dedicated to visual cortex and beyond. Many reasons validate a book assembling chapters written by active researchers. Each has the opportunity to bind together data and explore original ideas whose fate will not fall into the hands of uncompromising reviewers of traditional journals. This book focuses on the cerebral cortex with a large emphasis on vision. Yet it offers the reader diverse approaches employed to investigate the brain, for instance, computer simulation, cellular responses, or rivalry between various targets and goal directed actions. This volume thus covers a large spectrum of research even though it is impossible to include all topics in the extremely diverse field of neurosciences