31 accepted papers
Reduced traction limits the ability of mobile robotic systems to resist or apply large external loads, such as tugging a massive payload. One simple and versatile solution is to wrap a tether around naturally occurring objects to leverage the capstan effect and create exponentially-amplified holding
Prior work has addressed control of continuous jumping using touchdown angle from flight, but greater precision can be obtained by directing individual leaps using liftoff angle from stance. We demonstrate targeted leaping as well as balanced landingon a narrow foot with a small, single leg hopping
Recent work in the design of mechanical systems for terrestrial locomotion has indicated successful strategies for increasing the energetic performance of a robotic locomotor without upgrading its actuator system. We apply one such strategy, termed power modulation, in a new way: for the design of a…
Automatic repair of mechanical structures would enable a robot to recover or improve functions after physical damage. Little work exists on real-world execution of automatic repair in robotic systems. State-of-the-art takes a modular approach where the robotic system is modular and a replacement mod…
Much current study of legged locomotion has rightly focused on foot traction forces, including on granular media. Future legged millirobots will need to go through terrain, such as brush or other vegetation, where the body contact forces significantly affect locomotion. In this work, a (previously d…
We develop a drift-free roll and pitch attitude estimation scheme for monopedal jumping robots. The estimator uses only onboard rate gyroscopes and encoders and does not rely on external sensing or processing. It is capable of recovering from attitude estimate disturbances and, together with onboard…
Although reinforcement learning methods can achieve impressive results in simulation, the real world presents two major challenges: generating samples is exceedingly expensive, and unexpected perturbations or unseen situations cause proficient but specialized policies to fail at test time. Given tha…
OpenRoACH is a 15-cm 200-gram self-contained hexapedal robot with an onboard single-board computer. To our knowledge, it is the smallest legged robot with the capability of running the Robot Operating System (ROS) onboard. The robot is fully open sourced, uses accessible materials and off-the-shelf…
The minimalist robot designs typically employed in swarms and teams can fall and get trapped when traversing irregular terrain. To protect against this contingency the design could add a specialized escape actuator, but each actuator drives up cost multiplicatively for the whole team. Instead, the e…
Millirobots are a promising robotic platform for many applications due to their small size and low manufacturing costs. Legged millirobots, in particular, can provide increased mobility in complex environments and improved scaling of obstacles. However, controlling these small, highly dynamic, and u…
Model-free deep reinforcement learning algorithms have been shown to be capable of learning a wide range of robotic skills, but typically require a very large number of samples to achieve good performance. Model-based algorithms, in principle, can provide for much more efficient learning, but have p…
We developed a deadbeat foot placement hopping controller for an untethered monopedal robot, Salto-1P. The controller uses a third order Taylor series approximation to an offline dynamic model and performs well on the physical platform. The robot demonstrated precise foot placement even on trajector…
Due to high impact forces and low duty cycles, monopedal jumping robots are particularly susceptible to failure from a slipping foot. Spines provide a solution to reduce slip, but there has been little research on how to effectively engage them into a surface with a dynamic jumping robot. Previous r…
This paper analyzes and implements two novel turning strategies for underactuated legged robots that leverage contact of an active tail against terrain. The first strategy produces a sustained turn with a tail dragging against the ground during forward locomotion. The second strategy produces a rapi…
Soft material robots are attractive for safe interaction with humans and unstructured environments due to their compliance and low intrinsic stiffness and mass. These properties enable new capabilities such as the ability to conform to environmental geometry for tactile sensing and to undergo large…
In this paper we address the problem of multi-robot localization with a heterogeneous team of low-cost mobile robots. The team consists of a single centralized observer with an inertial measurement unit (IMU) and monocular camera, and multiple picket robots with only IMUs and Red Green Blue (RGB) li…
As small legged robots for search and rescue are deployed in collapsed buildings with unstructured terrain and steep drop-offs, they run the risk of flipping over and becoming incapacitated. A single degree of freedom low-mass tail is added to a 77.5 g, 18 cm long VelociRoACH legged robot with prote…
Legged robots can explore unstructured environments more effectively than wheeled robots, but high turning rate tracking is still a challenging problem, particularly on varying surfaces. Previous steering methods with small robots have shown high turn rates, but usually only on a limited set of surf…
This paper presents a novel manufacturing paradigm for constructing origami-inspired pop-up robots for future space exploration missions. The new approach uses a textile-enhanced rigid-flex printed circuit board (PCB) to implement a folding robot chassis using robust, spaceflight-tolerant materials,…
In this work we present a new robotic system, Salto-1P, for exploring extreme jumping locomotion. Salto-1P weighs 0.098 kg, and has an active leg length of 14.4 cm. The robot is able to perform a standing vertical leap of 1.25 m, continuously hop to heights over 1 m, and jump over 2 m horizontally.…
Ribbon folding is a new approach to structure formation that forms higher dimensional structures using a lower dimensional primitive, namely a ribbon. In this paper, we present a novel algorithm to address path planning for ribbon folding of multi-link planar structures. We first represent the desir…
New work in robotics targets the development of controllable agile motions such as leaping. In this work, we examine animal and robotic systems on the metric of jumping agility and find that animals can outperform the most agile robots by a factor of two. These specially adapted animals use a jumpin…
In this paper, we propose a trajectory-adjustable integrated milli-scale jumping-crawling robot with improved ability to overcome obstacles compared to a robot that can only crawl. The robot employs a novel jumping module with enhanced energy storing-capacity and a height-adjustable active trigger.
Animals and robots alike face challenges of flipping-over as they move in complex terrain. Small insects like cockroaches can rapidly right themselves when upside down, yet small fast-running legged robots are much less capable of ground-based self-righting. Inspired by the discoid cockroach that op…
This paper details a method for identifying a set of piece-wise affine linear models that can be used for control design for flapping-winged flight. The paper focuses on diving maneuvers as the application for these models. The flight conditions during the dive are segmented into separate dynamicall…
Automatic folding has drawn increasing attention in robotics research in the past ten years. The focus has been on folding two-dimensional (2D) sheets into three-dimensional (3D) structures, but little work has been done on how structures may be formed by folding ribbons. Here we propose the concept
Cooperation primitives for climbing steps were developed for a system of two 10 cm long VelociRoACH hexapedal legged robots with a removable connection. When performed sequentially, the set of primitives allow the team of two robots to climb a step on the order of their body length. These primitives
Collapsible leg spines found on insects and spiders provide a passive mechanism for increased traction while running over complex terrain. In this paper we use this architectural advantage as biological inspiration to increase the useful work in pulling a load with a VelociRoACH, a high speed terres…
In this work, we develop a cooperative launching system for a 13.2 gram ornithopter micro-aerial vehicle (MAV), the H2Bird, by carrying it on the back of a 32 gram hexapedal millirobot, the VelociRoACH. We determine the necessary initial velocity and pitch angle for take off using force data collect…
Mobile robot contact sensing can be useful for navigation and manipulation with small robots. In this work, we present a low-cost, 18.7 gram force-torque sensor for a 10 cm hexapedal millirobot. A planar array of photointerrupters, rigidly attached to the structure of the robot, is used to measure t…
The X2-VelociRoACH is a 54 gram experimental legged robot which was developed to test hypotheses about running with unnaturally high stride frequencies. It is capable of running at stride frequencies up to 45 Hz, and velocities up to 4.9 m/s, making it the fastest legged robot relative to size. The…