ModLab UPenn the modular robotics laboratory at the university of pennsylvania


Evaluating Older Adults’ Interaction with a Mobile Assistive Robot

We present findings from two deployments of an autonomous mobile robot in older adult low income Supportive Apartment Living (SAL) facilities. Design guidelines for the robot hardware and software were based on query of clinicians, caregivers and older adults through focus groups, member checks and surveys, to identify what each group believed to be the […]

A Decentralized Algorithm for Self Assembling Structures with Modular Robots

Recent work in the field of bio-inspired robotic systems has introduced designs for modular robots that are able to assemble into structures (e.g., bridges, landing platforms, fences) using their bodies as the building components. Yet, it remains an open question as to how to program large swarms of robotic modules so that the assembly task […]

Modular Robot Connector Acceptance by Configuration Space Analysis

Attachment and detachment between modules is critical for modular robot reconfiguration, and is a key design area for these systems. By re-purposing the interpretation of a well-known motion planning tool in configuration space obstacles for its encoding of contact geometry, we have developed a method for determining a metric of the region of error tolerance […]


Piccolissimo is the smallest self-powered flying vehicle (to the best of our knowledge). Thanks to its passive stability, it can fly with only one actuator. This makes it simple and low cost to construct and less likely to have a component fail.

The EP-Face Connector

We present the EP-Face connector, a novel connector for hybrid chain-lattice type modular robots that is high- strength (88.4N), compact, fast, power efficient, and robust to position errors.

An End-to-End System for Accomplishing Tasks with Modular Robots

Best Systems Paper, RSS 2016.  In this paper, we present an end-to-end system for addressing tasks with modular robots, and demonstrate that it is capable of accomplishing challenging multi-part tasks in hardware experiments.


SMORES-EP is a modular robot designed and built at the University of Pennsylvania, and used by researchers at Penn and Cornell. SMORES stands for Self-Assembling MOdular Robot for Extreme Shapeshifting, and EP refers to the Electro-Permanent magnets the modules use to connect.

Computer-Aided Compositional Design and Verification for Modular Robots

To take full advantage of the flexibility of a modular robot system, users must be able to create and verify new configurations and behaviors quickly. We have developed a design framework that facilitates rapid creation of new configurations and behaviors through composition of existing ones, and tools to verify configurations and behaviors as they are […]

American Helicopter Society Student MAV Challenge 2015

We have developed a low-cost, lightweight coaxial-rotor MAV capable of full attitude control using just two actuators. The vehicle provides real-time telemetry and high-quality video to a ground station which can be used to remotely pilot the vehicle. The design integrates the underactuated rotor system developed in the lab with parts of cheap helicopter toys […]

Passive Stability of MAVs Without Angular Momentum

We modeled and built Micro Aerial Vehicles (MAVs) that naturally hover without any sensing or control. These types of vehicles, called passively stabilized vehicles, can be made less complicated, more robust, and at lower cost with the addition of simple, yet carefully designed, stabilizer sails.

Modular Robot Design Embedding

We have developed an algorithm that automatically detects embeddability of modular robot configurations. Simply put, a given design embeds another design if it can replicate its structure, and therefore simulate its functionality. We introduce a novel graph representation for modular robots, and formalize the notion of embedding through topological and kinematic conditions. Our algorithm involves […]

Underactuated Rotor for Simple Micro Air Vehicles

We extract thrust, roll, and pitch authority from a single propeller and single motor through an underactuated mechanism embedded in the rotor itself. This allows new types of conventionally-capable micro air vehicles now requiring only two motors. This contrasts with the servos and linkages of conventional helicopters or the four drive motors in quadrotors.

Low-cost Laser Range Finder

The goal for this project is to make a low-cost but high-speed , very small and reliable laser range finder. The idea is to talk to a small camera, and obtain the laser line position and send out the data line by line in real-time.


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, while using only a position sensor, which is already required for servo control. We call this compensation "Anticogging".

Passive Stability of a Single Actuator MAV

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.

Little Robots to move Big Things

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.

Hybrid Exploration Robot for Air and Land Deployment (H.E.R.A.L.D)

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.

Tactically Expandable Maritime Platform (T.E.M.P.)

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

ICRA Robotic Planetary Contingency 2008 featured four teams competing in multiple, time sensitive, emergency scenarios with modular robotic solutions.

Structure synthesis on-the-fly

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.

Search and Rescue

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.

Module Brake

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.

Factory Floor

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.

Self re-Assembly after Explosion

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.

Dynamic Locomotion of CKBot

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.

Quick Change End Effector

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.

Distributed Communication Fault Tolerance

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.

Configuration Recognition

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.

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