EAGER: Reliable Control for Soft Robots through Sensor Placement

这个早期概念探索性研究资助(AGIRE)项目将创造新的基于传感器的控制算法，使软机器人能够使用新型的软光学传感器，以便对机器人和环境的变化做出实时反应。软机器人--即由橡胶等软材料制成的机器人--有可能彻底改变机器人的设计、制造和部署方式。快速成型技术可以在几个小时而不是几个月的时间内制造出新的机器人，机器人设计可以定制以适应机器人的环境和任务，而且这些机器人本质上是安全的，可以与人密切互动。然而，目前在复杂环境中可靠、长时间使用软机器人的例子很少。这种缺乏健壮性的行为的原因包括很难对机器人与环境的相互作用进行建模，例如在沙子和混凝土上行走时腿弯曲的方式，软执行器相对于刚性执行器的故障率更高，以及相对缺乏与传统刚性传感器相比的良好的软传感器。这个项目解决了所有这三个挑战，因为软测量在物理上是健壮的，与新的控制算法一起，大大减少了对精确模型的需求。这个迫切的项目的目标是收集初步数据，并评估共同设计泡沫机器人控制和传感器放置的可行性，这些机器人嵌入可伸缩的光波导，可以用来感知软机器人S身体的变形。该项目的成果将推进软机器人的愿景，这种机器人可以在各种环境中进行可预测和可靠的控制。这种新型的软光学传感器可以以多种配置嵌入整个执行器中；因此，可以考虑到控制目标来设计放置。由于软执行器的精确建模困难，特别是那些可以创建不同形状的软执行器，为了给软机器人提供可靠和可重复的控制，必须在软机器人的身体中嵌入传感器。传感器提供的信息，加上机器人运动的简化模型，应该用来控制机器人。该项目将产生(I)可从嵌入泡沫致动器中的可伸缩光波导获得的信息的特征，(Ii)由于制造限制以及传感器对泡沫致动器和彼此的交叉影响而可以从多个嵌入式传感器收集的质量、空间分辨率和信息类型的物理限制，以及(Iii)给定固定的多腿机器人返回所需的传感器位置和反馈控制器的算法，该反馈控制器将在特定地形上产生可预测的运动。要实现软机器人的可靠和稳健控制，真正的突破将需要一种将传感、驱动和控制相结合的全新方法，其中控制目标和物理限制决定了传感器的放置和反馈控制。

This EArly-concept Grant for Exploratory Research (EAGER) project will create new sensor-based control algorithms to enable soft robots to use a novel soft optical sensor in order to react in real time to changes in the robot and the environment. Soft robots -- that is, robots made of soft materials such as rubber -- have the potential to revolutionize the way robots are designed, manufactured and deployed. Rapid prototyping techniques can produce new robots in a matter of hours, not months, robot design can be customized to fit both the robot's environment and task, and these robots are inherently safe, enabling close interaction with people. However, there are currently few examples of reliable, long duration use of soft robots in complex environments. Reasons for this lack of robust behavior include the difficulty of modeling the robot's interaction with the environment, for example the way the legs bend when walking on sand vs. concrete, the higher failure rate of soft actuators versus rigid actuators, and relative lack of good soft sensors versus traditional rigid sensors. This project addresses all three of these challenges, because the soft sensors are physically robust and, together with the new control algorithms, greatly reduce the need for accurate models. The objective of this EAGER project is to collect preliminary data and assess the feasibility of co-designing control and sensor placement for foam-based robots embedded with stretchable optical waveguides which can be used to sense deformations in the soft robot?s body. The outcomes of this project will advance the vision of soft robots that can be predictably and reliably controlled in a variety of environments. The novel soft optical sensors can be embedded throughout the actuator in a plurality of configurations; therefore, the placement can be designed with the control objective in mind. Due to the difficulty in exact modeling of soft actuators, especially those that can be created in different shapes, in order to create reliable and repeatable control for soft robots, sensors must be embedded in the body of the soft robot. The information the sensors provide, together with simplified models of robot motion, should be used to control the robot. This project will produce (i) a characterization of the information that can be obtained from a stretchable optical waveguide embedded in a foam actuator, (ii) physical limits on the quality, spatial resolution, and type of information that can be collected from multiple embedded sensors due to manufacturing constraints and the cross-influence of the sensors on the foam actuator and each other, and (iii) an algorithm that given a fixed multi-legged robot returns the required sensor placements and the feedback controller that will create predictable motions over a specific terrain. The real breakthrough that will enable reliable and robust control of soft robots will require a radical new approach to combining sensing, actuation and control, where the control objective, together with physical limitations, determines sensor placement and feedback control.