Design and Optimisation of Virtual Mechanism Controllers With Applications in Robotic Surgery

The challenge of robot control design remains central to enabling safe, effective, and intuitive robotic systems. This thesis explores virtual mechanism control, a structured approach to designing robot controllers using virtual mechanical components. This method offers advantages in simplicity of implementation, ease of design, and intuitive yet flexible behaviour, while maintaining strong theoretical foundations through its connections to passivity-based control, impedance control, port-Hamiltonian control, virtual model control, and virtual fixtures. The primary application domains considered in this work are in robotic surgery, with a focus on robot-assisted laparoscopy and the remote-centre-of-motion constraint, as well as robot-assisted orthopaedic surgery. The key challenges in these applications are ensuring safety and human robot collaboration, which virtual mechanism control is well positioned to address. This thesis presents several contributions, including: (1) a formalisation of virtual mechanism control, (2) new controllers tailored for specific surgical tasks, (3) novel methods for tuning virtual mechanism controllers, and (4) a software toolbox that facilitates the design, simulation, and implementation of these controllers. The developed software has been open-sourced to support further research and adoption of virtual mechanism control in robotic applications. By integrating classical control principles with a structured, physically intuitive framework, this work advances the field of robot control design, particularly for safety-critical and human-interactive applications such as robotic surgery.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2025

Author dc:creator

• Larby, Daniel

Advisor dc:contributor.advisor

• Forni, Fulvio

• Impedance Control
• Optimal Control
• Passivity Based Control
• Robotics
• Virtual Mechanism Control

Licence

• https://www.repository.cam.ac.uk/bitstreams/e99fbf55-1fda-413f-951f-31c3c6e8d82e/download
• http://purl.org/NET/rdflicense/allrightsreserved

Language dc:language

eng

Author Identifier

0000-0003-1153-4166

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/388621