Smooth motion is critical to robotic applications like haptics or those requiring high precision force control. These systems are often direct-drive, so any torque ripple in the motor output must be minimal. Unfortunately, low inherent torque ripple motors are expensive. We came up with a method to map and suppress torque ripple from cogging torque so low cost motors can perform as well as expensive ones.
In an effort to build one of the world's smallest flying vehicles, we built a flying vehicle with only two moving parts connected by one motor. Because the vehicle cannot control its attitude with its one actuator, passive stability is a required trait, so we derived design requirements for making passively stable vehicles.
Our mobile telepresence robot is fitted with a robotic manipulator that will allow a person to virtually manipulate the avatar environment. We have shown our robot called "Persona" to be capable of moving up and down ramps, use elevators, manipulate objects such as chess pieces, and to lift and transport loads up to 4.5 kg.
The DARPA Robotics Challenge (DRC) is a competition sponsored by DARPA to encourage rapid, innovative development in the field of humanoid robotics. Modlab participated with Penn as a part of Team THOR and Dr. Lee's lab, in an alliance with Virginia Tech, Robotis Inc, and Harris Corp. The Trials were held from Dec 20-21, 2013, with sixteen teams each providing a robot to complete eight tasks designed to simulate disaster recovery scenarios.
The Little Robots to move Big Things project is motivated by the paradigm in modern robotics that most robots are incapable of manipulating objects that are even a small proportion of the robot's mass. This project seeks to overturn this trend by using small robots to create large forces by leveraging the reaction forces created through interactions with fixed objects in the workspace.
The SEAL Pack is versatile, portable, and quickly deployable, similar to the Navy SEALs. SEAL stands for SEa, Air, and Land and the SEAL Pack is versatile enough to traverse all three. The SEAL Pack is transported in a compact way, and can be unpacked into either a car, boat, or quadrotor in a matter of minutes thanks to its modular design.
The Modular Robotics Laboratory (Dean Wilhelmi, Stella Latscha, Matthew Piccoli) collaborated with other technology studios from Penn (IKStudio under Simon Kim) and Harvard, as well as dance studio Carbon Dance Theatre (co-choreographers: Meredith Rainey & Marcel W. Foster) to create a dance performance blending art and technology called Science Per Forms.
A team of five mechanical engineering seniors, in collaboration with the Modular Robotics Laboratory and under the guidance of Dr. Mark Yim, have designed a search and rescue research platform intended to address limitations of current search and rescue robots and introduce a novel form factor and integration technique into the field.
We have built a system of shipping container sized robotic boats that can hook onto each other. We demonstrate the conceptual design of a system that is capable of constructing bridges and various shaped islands that can be made compliant to waves.
Docking and undocking are common activities for robots (modular robots in particular). The relative frequency of this operation behooves us to ensure reliable alignment under uncertain conditions. We present a new face geometry that is numerically superior to existing alignment geometries. This geometry is intended for two-dimensional reconfigurable robots.
Connection mechanisms are critical to modular reconfigurable systems. The ModLock manual connection system is both fast to attach/detach and strong. This low cost, low profile connection system has been demonstrated on a variety of robot configurations including legged walkers, flying quadrotors and wheeled robots.
The design of this system called SMORES (Self-assembling MOdular Robot for Extreme Shapeshifting) is capable of rearranging its modules in all three classes of reconfiguration; lattice style, chain style and mobile reconfiguration. Modules are independently mobile and are capable of self-assembly from a collection of disconnected modules.
ICRA Robotic Planetary Contingency 2008 featured four teams competing in multiple, time sensitive, emergency scenarios with modular robotic solutions.
Hard foam can be used to synthesise a body on-the-fly, allowing us to spray a body for this quadruped. Each of the limbs comprises three CKBot modules, in a configuration similar to that used in the self-assembly after explosion project.
Can small man-portable robots aid the transport of incapacitated victims? This work received the Best Paper Award at the 2009 IEEE International Workshop on Safety, Security, and Rescue Robotics.
The XBot system is a lattice style modular self-reconfigurable robot that uses external actuation to deterministically reconfigure XBot modules. Using the principle of external actuation facilitates module miniaturization as modules do not require motors or servos to reconfigure.
Modules in the Right Angle Tetrahedron Chain Externally Actuated Testbed (RATChET) system can be programmed to form arbitrary shapes. Using an external manipulator to fold the chain under the force of gravity simplifies the module design since they do not require a motor at each joint.
The Dysc is a new MAV with counter-rotating rotors that uses gyroscopic moments for attitude control. The two rotors are fixed pitch, eliminating the need for complex mechanisms like the swashplate, leading to lower cost and easier maintenance when compared to traditional helicopter configurations. In addition, the Dysc has the potential for higher agility than quadrotors.
We have designed a joint-locking mechanism for a new chain-style modular reconfigurable robot. This mechanism will enable the robot to perform a wide array of tasks such as dynamic motion and bio-inspired locomotion while consuming less power.
The factory floor is an experimental robotic system for the construction of passive robotically-reconfigurable truss structures. The macroscopic goal of this work is to embed autonomous reconfigurability into human-built systems.
The CKbot (Connector Kinetic roBot) is a chain style modular robot. It is designed to be fast and inexpensive while small enough to fit inside a 3 inch tube. It is manually reconfigurable into any shape while also allowing attachments such as wheels, grippers, IR proximity sensors and camera modules.
A car bumper is designed to crumple upon impact and protect the driver. A ski boot will detach from the ski to prevent injury to the ankle. Likewise a CKbot assembly falls apart when it is kicked, however CKbot can put itself back together again.
CKBot is designed to be fast allowing it to achieve dynamic locomotion. Given that CKBot is reconfigurable gives us the unique ability to research different types of dynamic locomotions in different morphologies all with the same hardware.
This prototype allows PR2 to change end-effectors on his own. He could trade in his hand for a different gripper, a screwdriver, or even a sensor such as a camera. The quick release mechanism makes it easy for him to attach and detach and it also features electrical connections to transfer power and communication.
An advantageous feature of modular robots is the applicability to system fault tolerance. With redundant units and parallel processing facilities, modular robots have the capability or potential to account for certain types of failures within its system. This research presents work on communication fault tolerance with CKBot.
The advantage of reconfiguration is central to modular robotic systems. With this benefit, however, comes a complex and interesting challenge: how does a modular robot recognize which shapes are useful or familiar? The ability for a modular robot to determine which configurations are needed for various tasks is a fundamental requirement for increased autonomy.