Modular Robotic Vehicle (MRV)
robotics automation and control
Modular Robotic Vehicle (MRV) (MSC-TOPS-74)
Battery powered electric vehicle with full drive by wire system
Overview
Innovators at the NASA Johnson Space Center in collaboration with an automotive partner have developed the Modular Robotic Vehicle (MRV). This fully electric vehicle is well-suited for busy urban environments, industrial complexes, or large resort areas. The MRV combines a number of innovative technologies that are available for licensing as a whole system or individually as components. The MRV has no mechanical connections to the propulsion, steering, or brake actuators-- instead the driver relies on control inputs being converted to electrical signals and transmitted by wire to the motors within the vehicle. The MRV has a fully redundant, fail-operational architecture that is paramount to the safe operation of a by-wire system. The MRV is driven by four independent wheel modules, called e-corners. Each e-corner can be rotated +/- 180 degrees about its steering axis. Imagine being able to parallel park by simply driving sideways into a tight spot with ease. With the new MRV technology, this dream is now a reality.
The Technology
The Modular Robotic Vehicle (MRV) is a vehicle designed for transportation in congested areas. The MRV is relatively small, easy to maneuver and park. The MRV was designed without a central power plant, transmission, fuel tank, and direct mechanical linkages between driver input devices and the actuators used to accelerate, brake and/or steer the car. These core vehicle functions are located at the corners of the vehicle in a modular electric corner assembly or eCorner. Because the MRV uses a by-wire control system, substantial space and weight is conserved compared to conventional designs. Moreover, the functional capabilities that are provided by the individual eCorners enable control of the vehicle in a variety of different operating modes.
The eCorners provide significant flexibility in driving options. For example, the driving mode can be switched so that all four wheels point and move in the same direction achieving an omni-directional motion or all wheels can be pointed perpendicular to the center of the vehicle allowing rotation around its center axis. This mode makes some driving maneuvers like parallel parking as easy as driving next to the spot, turning the wheels 90 degrees, and driving into the open spot in a sideways motion. Each eCorner includes its own redundancy to protect for electrical failures within the systems. The driver can choose to control the vehicle with a conventional steering wheel or add inputs through a multi-axis joystick for additional control in some of the more advanced drive modes. The vehicle has the propulsion motors located inside of each eCorner with the capability of producing 190 ft-lbs of torque with a current top speed of 40 mph. An active thermal control loop maintains the temperatures of these high powered motors and a separate thermal loop cools the avionics and the custom lithium-ion battery packs. The linked vehicles are able to exchange or share control data and electrical power. Finally, the MRV has remote driving control capability.
Benefits
- Lighter and efficient due to eCorner design
- Full drive-by-wire systems (propulsion, steering and braking)
- Redundant fail-operation architecture
- Four independent wheel modules
- 180 degree steering actuation
- Liquid cooled in-wheel propulsion motors
- Remote driving capability
- Software allows for fine control of steering and torque of each wheel individually. This allows for vehicle dynamic algorithms not possible in traditional automobiles
Applications
- Automotive
- Industrial Vehicles
- Entertainment
- Motorized Wheelchairs
- Transportation, Delivery and Service
- Airport Transportation
- Miniaturized Mobility Systems
Similar Results
Space Suit RoboGlove (SSRG)
NASA is currently developing the next generation space suit for future missions, including the optimization of space suit gloves. When non-assisted space suit gloves are coupled to a pressurized suit and operated in a vacuum, they tend to limit the range of motion of an astronaut's hand to as little as 20% of normal range. Many of NASA's future missions will be in challenging environments where an astronauts hand dexterity will be critical for the success of NASA missions. Innovators at JSC have improved the performance on the second-generation, robotically assisted SSRG, to reduce exertion and improve the hand strength and dexterity of an astronaut in situ.
The SSRGs system detects user finger movements using string potentiometers and contact with objects using force-sensitive resistors (FSRs). FSRs are imbedded in the distal and medial phalanges, palmar side of the glove. To move a finger, an actuator pulls a tendon through a Bowden Cable system which transfers mechanical pulling force of an inner cable relative to a hollow outer cable, like the brakes on a bicycle, as seen in the Figure below. An improved controller commands the new, more powerful linear actuator to drive tendon operation while minding custom controller parameters inputted through a digital editor tool.
The Space Suit RoboGlove is at TRL 6 (system/subsystem model or prototype demonstrated in a relevant environment) and it is now available for licensing. Please note that NASA does not manufacture products itself for commercial sale.
Robonaut 2: Industrial Opportunities
NASA, GM, and Oceaneering approached the development of R2 from a dual use environment for both space and terrestrial application. NASA needed an astronaut assistant able to function in space and GM was looking for a robot that could function in an industrial setting. With this in mind, R2 was made with many capabilities that offer an enormous advantage in industrial environments. For example, the robot has the ability to retool and vary its tasks. Rather than a product moving from station to station on a conveyor with dozens of specialized robots performing unique tasks, R2 can handle several assembly steps at a single station, thereby reducing manufacturing floor space requirements and the need for multiple robots for the same activities. The robot can also be used in scenarios where dangerous chemicals, biological, or even nuclear materials are part of the manufacturing process.
R2 uses stereovision to locate human teammates or tools and a navigation system. The robot was also designed with special torsional springs and position feedback to control fine motor movements in the hands and arms. R2's hands and arms sense weight and pressure and stop when they come in contact with someone or something. These force sensing capabilities make R2 safe to work side-by-side with people on an assembly line, assisting them in ergonomically challenging tasks or working independently.
This NASA Technology is available for your company to license and develop into a commercial product. NASA does not manufacture products for commercial sale.
Regolith Advanced Surface Systems Operations Robot (RASSOR) Excavator
Regolith excavation is desired in future space missions for the purpose of In Situ Resource Utilization (ISRU) to make local commodities, such as propellants and breathing air, and to pursue construction operations. The excavation of regolith on another planetary body surface, such as the Moon, Mars, an asteroid, or a comet is extremely difficult because of the high bulk density of regolith at lower depths. Additionally, because of the low gravity in these space surface environments, the mass of the excavator vehicle does not provide enough reaction force to enable the excavation blade to penetrate the regolith if traditional terrestrial methods are used.
RASSOR uses counterrotating bucket drums on opposing arms to provide near-zero horizontal and minimal vertical net reaction force so that excavation is not reliant on the traction or weight of the mobility system to provide a reaction force to counteract the excavation force in low-gravity environments. The excavator can traverse steep slopes and rough terrain, and its symmetrical design enables it to operate in reverse so that it can recover from overturning by continuing to dig in the new orientation. The system is capable of standing up in a vertical position to dump into a receiving hopper without using a ramp. This eliminates the need for an onboard dump bin, thus reducing complexity and weight.
During loading, the bucket drums excavate soil/regolith by scoops mounted on the drums exteriors that sequentially take multiple cuts of soil/regolith while rotating at approximately 20 revolutions per minute. During hauling, the bucket drums are raised by rotating the arms to provide clearance above the surface being excavated. The mobility platform can then travel while the soil/regolith remains in the raised bucket drums. When the excavator reaches the dump location, the bucket drums are commanded to reverse their direction of rotation, which causes soil/regolith to be expelled out of each successive scoop. RASSOR has wireless control, telemetry, and onboard transmitting cameras, allowing for teleoperation with situational awareness. The unit can be programmed to operate autonomously for selected tasks.
Robotic Inspection System for Fluid Infrastructures
The Robotic Inspection System improves the inspection of deep sea structures such as offshore storage cells/tanks, pipelines, and other subsea exploration applications. Generally, oil platforms are comprised of pipelines and/or subsea storage cells. These storage cells not only provide a stable base for the platform, they provide intermediate storage and separation capability for oil. Surveying these structures to examine the contents is often required when the platforms are being decommissioned. The Robotic Inspection System provides a device and method for imaging the inside of the cells, which includes hardware and software components. The device is able to move through interconnected pipes, even making 90 degree turns with minimal power. The Robotic Inspection System is able to display 3-dimentional range data from 2-dimensional information. This inspection method and device could significantly reduce the cost of decommissioning cells. The device has the capability to map interior volume, interrogate integrity of cell fill lines, display real-time video and sonar, and with future development possibly sample sediment or oil.
Affordable Vehicle Avionics (AVA)
Significant contributors to the cost of launching nano- and micro-satellites to orbit are the costs of software, and Guidance, Navigation and Control (GNC) avionics systems that steer, navigate and control the launch vehicles, sequence stage separation, deploy payloads, and pass data to Telemetry. The high costs of these GNC avionics systems are due in part to the current practice of developing unique, custom, single-use hardware and software for each launch, and requiring high-precision measurements of position and attitude states. NASA Ames Research Center has developed and tested a low-cost avionics system prototype called Affordable Vehicle Avionics (AVA). AVA integrates a low-cost moderately-precise sensor suite with an advanced error-correcting software package to provide GNC for space launch vehicles in a package smaller than a multilayer sandwich (100 mm x 120 mm x 69 mm; 4in x 4.7in x 2.7in), and with a mass of less than 0.84kg (2lbs). The invention provides a common suite of avionics components and demonstration software that deliver affordable, capable GNC with flexible I/O which is applicable to a variety of nano/micro-sat launch vehicles at less than 10 percent of the cost to procure current state-of-the-art GNC avionics. Affordable Vehicle Avionics' (AVA's) approach to drastically reduce costs includes: (1) use of low-cost "tactical-grade" Commercial-off-the-Shelf MicroElectroMechanical Systems (MEMS) inertial measurement unit, wherein adequate navigation precision is achieved by fusing outputs from a Global Positioning System receiver, inertial sensors and a magnetic field vector sensor in an extended Kalman filter formulation that corrects inertial sensor biases; (2) a streamlined "cookbook" approach to define an effective process for launch vehicle developers to design, simulate, verify and support assembly, integration and testing of their SLVs, driven by high-fidelity six degrees of freedom SLV simulations and real-time hardware-in-loop tests to validate guidance, navigation and control for early test flights.
Development Status:
As of spring 2020, AVA has flown twice in its current configuration on a suborbital platform. Its navigation and control functions were successfully demonstrated for roll-rate control within a tight deadband onboard the first flight test, and it successfully issued attitude pointing commands to a failed reaction control subsystem and it issues issued a rocket-motor ignition command on a second flight test. To date, failure of SLV components other than AVA (e.g., electrical power) has precluded demonstration of navigation and control of an orbital or sub-orbital launch system, which remains to be demonstrated.
AVA development was accomplished using a single magnetometer-based magnetic field vector sensor to provide attitude observability during free-fall (inter-stage coast periods). Therefore, the current tested AVA configuration is susceptible to magnetic/electric fields produced by other components and payloads onboard the SLV, so care must be exercised to either mount AVA well away from sources of such fields and or to incorporate magnetic/electric field barriers on field emitters if separation from emitters is inadequate. Also, licensees may wish to provide new AVA inputs from a pair of external horizon sensors to provide more accurate attitude navigation during coast phases of the SLV mission.