VectorNavS VN-100 Enhances Ghost Robotics’ Minitaur Platform
VectorNav technologies has announced that it’s VN-100 Inertial Measurement Unit/Attitude and Heading Reference System (IMU/AHRS) will be integrated into Ghost Robotics’ Minitaur, a cutting-edge legged unmanned ground vehicle (UGV). This advanced IMU provides precise and rapid attitude data,crucial for the Minitaur’s innovative direct-drive leg mechanism,which allows it to navigate various challenging terrains with agility,including running,jumping,and climbing.
Minitaur: A New Era in Legged Robotics
The Minitaur is a versatile, medium-sized robot designed for high-speed and dynamic movement, making it ideal for developing commercial UGVs, conducting advanced locomotion research, and facilitating machine learning applications. Its unique leg architecture and specialized motor controllers offer significant advantages over traditional UGV designs.
Challenges of Legged Locomotion
Achieving effective legged locomotion involves complex coordination and balance, necessitating precise state estimation to manage multiple degrees of freedom. the Minitaur utilizes a bounding gait, where its direct-drive motors and innovative leg design mimic a “spring-like” action, enabling it to traverse rough and uneven surfaces.This bounding motion posed a significant challenge in sourcing an inertial measurement solution capable of delivering accurate attitude estimations across the Minitaur’s dynamic range. as a notable example, the robot can reach speeds of up to 2 m/s (approximately 4.5 mph), achieve angular velocities of 10 rad/s (about 570°/s), and endure impacts of up to 10 g when landing from jumps.
Transitioning to Higher Accuracy IMUs
Initially,the Ghost Robotics team experimented with a commercially available uncalibrated IMU but soon recognized the need for greater accuracy to meet their performance goals.They transitioned to an industrial-grade IMU from another supplier, which improved accuracy but lacked the necessary range for the high angular rates experienced by the Minitaur. While collaborating at the University of pennsylvania’s GRASP (General Robotics, Automation, Sensing & Perception) Laboratory, the team observed other researchers successfully using the VN-100 IMU/AHRS for SLAM (simultaneous localization and mapping) in small autonomous aerial vehicles. “The VN-100 has an outstanding reputation and met all our testing requirements,” stated Gavin Kenneally, co-founder of Ghost Robotics.
Seamless integration of VN-100
The team opted to incorporate the VN-100 Surface Mount Device (SMD) into the Minitaur’s printed circuit board (PCB). “The SMD option allows for tight integration of the VN-100 into our custom electronics without the need for additional housing,” Kenneally explained. “Moreover, the SMD version supports SPI interface, which can operate at considerably higher clock speeds compared to UART baud rates,” added Avik de, co-founder of Ghost Robotics.
Optimizing Performance and Future Capabilities
The compact size, lightweight design, low power consumption, and high performance of the VN-100 have enabled Ghost Robotics to enhance the Minitaur’s battery efficiency, allowing it to remain stationary for up to 6.75 hours and run at full speed for 20 minutes. An additional benefit of the VectorNav Industrial Series SMDs is their common footprint, pin-out, and protocol, which will allow Ghost Robotics to implement a fully functional Inertial Navigation System (INS) in future models using the VN-200. This integration will enable features such as waypoint navigation, return-to-home functionality, and geolocation capabilities.
Looking Ahead: market interest and Future Developments
“We are extremely pleased with the VN-100 and the support provided by VectorNav. The bipedal capabilities of the Minitaur are made possible by this high-performance IMU,” remarked De. Ghost Robotics is garnering significant interest across research, commercial, and military sectors as they work towards launching their first commercially viable legged robot.The company plans to develop a comprehensive range of ruggedized,field-grade UGV platforms in the coming years.
