The OmniTread serpentine robot is designed to traverse extremely difficult terrain, such as the rubble of a collapsed building.
The OmniTread can also drive over sand and rocks. It can pass through small holes and climb over tall obstacles.

Innovations:

• Use of pneumatic bellows for joint actuation. Bellows are powerful, naturally compliant, and take up minimal space.
• Maximal coverage of all sides of all segments with extra wide moving tracks.
• Unique pneumatic control method allows simultaneous proportional control of stiffness and joint angles.
• The "drive shaft spine" is powered by a single electric motor in the center segment. The spine runs through the center of all segments and provides torque to all tracks.

We received from the DARPA MARS program a Segway Robotics Mobility Platform (RMP)

We equipped the Segway RMP with our precision FLEXnav proprioceptive* position estimation (PPE) system.

We equipped the Segway with obstacle avoidance capabilities.

 

In 1995 the Oak Ridge National Lab (ORNL) - required a highly accurate mobile robot for their "Mobile Mapper" project.

ORNL found that no commercially available robot met the requirements, while UM's CLAPPER came close.

HelpMate Robotics Inc. and UM built the first commercial CLAPPER, called OmniMate.

UM's Multi-Degree-of- Freedom (MDOF) vehicle is fully omni-directional (can travel in all directions and rotate at the same time).

Unique, patented compliant- linkage absorbs momentary controller errors to avoid wheel slippage.

Recovery from actuator failure: Vehicle can be moved and controlled remotely even after a motor, power amplifier, or other critical component fails.

OmniNav is a new method that provides obstacle avoidance for non-point, omnidirectional mobile robots.

Problem is more difficult than obstacle avoidance for point-like robots.

UM is currently investigating the feasibility of a method based on multiple VFH "act-on" points.

UM developed a new approach to navigating a mobile robot through narrow aisles.

Key requirement: entry, exit, and travel within the aisles be 100% collision-free

Requirement hard to meet with sonars, because of specular reflections and crosstalk causing false range readings.

UM's solution based on:

• optimized location of sensors
• only accurate radial range used readings for servoing.
• inaccurate range readings used only for "yes/no" decisions.

NASA-funded project aimed at developing a high-accuracy dead-reckoning system for the Mars Rover 2009 mission.

We built "Fluffy," a fully functional 1/2-scale clone of the NASA Fido-class Mars Rovers.

We implemented our Fuzzy Logic Expert Rule-based navigation (FLEXnav) method on Fluffy.

We optimized the FLEXnav system for the unique wheel slippage conditions on sandy soil.

Main Innovation: Wheel slippage detection and correction by slippage monitoring

UM developed benchmark test for odometric accuracy of mobile robots, called "UMBmark."

UM tested six different vehicle configurations with UMBmark:

• 1. TRC LabMate, differential drive.
• 2. Cybermotion K2A synchro drive.
• 3. CLAPPER MDOF vehicle.
• 4. Remotec Andros, tracked vehicle.
• 5. Andros with encoder trailer.
• 6. Smart Encoder Trailer (simulation).

Our pedestrian tracking system, also called "Personal Dead-reckoning" (PDR) system, tracks and records or transmits the location of a walking person relative to a known starting position.

• The PDR system works by using an Inertial Measuring Unit (IMU) mounted to the user's boot. Our innovative algorithms correct the drift of the accelerometers in the IMU with every step, thereby preventing the accumulation of errors.
• The PDR system requires no GPS or other beacon or reflector systems that must be preinstalled in the work environment.
• This makes the PDR system uniquely suitable for emergency responders or military personnel entering unprepared buildings.
• The PDR system does not require any training or matching to the user. It also works with different walking patterns: walking, jogging, stair climbing, even dancing!
• When equipped with a high-grade IMU, the PDR system produces position errors of under 2% of distance traveled for walks of up to 15 minutes.
• Accuracy degrades gracefully in longer walks.

Function:

• Records and transmits the position of a walking person.
• Is based on our PDR system, but is optimized for indoor use.

Features:

• Does not require GPS or Pseudo-GPS.
• Does not require beacons or any other external reference.
• Does not require user-specific calibration*.
• Records and streams 3-D position data in real time.
• Provides near-zero heading errors in walks of unlimited duration**.
• Provides position error <1% of distance traveled**.

Notes:
*Requires 25 seconds of standing still prior to any mission.
**These specs apply only to normal walking, inside buildings. Prolonged activities other than walking may result in the graceful degradation of accuracy.

Similar to NavChair approach, UM developed "NavBelt" for the blind.

Uses UM's obstacle avoidance: instead of issuing steering signals to the robot controller, NavBelt generates acoustic cues conveyed to the user via headphones.

NavBelt's limitations: Required hundreds of hours of training before users could respond to the acoustic cues in time, even at slow walking speeds.

UM developed "NavChair" for severely disabled users.

Some users cannot control their wheelchair accurately with a joystick, because of tremor or other limitations.

Obstacle avoidance on NavChair overcomes these problems:

User gives general direction of travel with joystick; NavChair follows this direction.

When obstacle is encountered, NavChair steers around it while trying to maintain user-specified direction as closely as possible.