Rolf Müller

Research Interests

• Bioinspired Robots
• Deep-learning for Sensing and Control
• Autonomy in Natural Environments

Bioinspired Robots

Mueller's group seeks to develop robots that can mimic the superior sensing abilities and mobility of bats that are able to hunt in dense natural environments. Bats have the most complicated flight apparatus across all biological and engineered systems that fly with about 20 discrete degrees of freedom in each wing. Similarly to the complexity of the wings, bats have about 20 muscles on each ear that deform the shape of the pinna as it diffracts the incoming biosonar echoes. Biomimetic reproductions are an important tools for understanding these complex mechanical systems for mobility and sensing.

Deep-learning for Sensing and Control

Bats live in complex environments and hence receive complex ultrasonic echoes that are superpositions of contributions from many reflecting facets (e.g., leaves in a foliage). Such "clutter echoes" have eluded interpretation in technical sonar for many decades. However, the ongoing revolution in the capabilities of deep-learning methods provide a unique opportunity to extract patterns from data that have previously resisted interpretation. Mueller's group is exploiting deep-learning methods to extract valuable information on complex environments from these "clutter echoes". Furthermore, the research employs transparent AI approaches to gain insight into what the informative signal features. Based on these insights, highly efficient neuromorphic approaches to extracting sensory information can be implemented. To tie sensing and robotics, Mueller's group is working on deep reinforcement learning methods that can integrate the control of the complex soft-robotic ears with the sensing.

Autonomy in Natural Environments

The efforts by Mueller's group on building biomimetic robots and equipping them with sensory capabilities based on deep-learning methods are aimed at achieving autonomous operation in complex natural environments. Uncontrollable outdoor environments pose the highest-level challenge to achieving autonomous operation of an engineered system. Pioneering work by Mueller's group has shown that seemingly challenging navigation tasks like finding a narrow passageway among foliage or identifying a location based on ultrasonic echoes that last only for a small fraction of a second. These technologies could have a transformative impact on applications in areas such as precision agriculture and forestry, environmental surveillance and clean-up, as well as national security (esp., in GPS-denied environments and underwater).

International Work

The research of Mueller's group has a strong international component, since it seeks to leverage Borneo's biodiversity as source for inspiration. This international venture is carried out in collaboration with the University of Brunei on the Island of Borneo, one of the world's most biodiverse regions. This given the research of Mueller's group the opportunity to observe bats from a large number of species in the field and hence better understand how the biosonar sensing and mobility of the animals is integrated into their natural habitats.