Dr. Haye Lau

Research Interests

My research topic is on optimal search for a target (victim, intruder etc) moving in indoor environments, which in essence boils down to finding discrete sequences of rooms/regions etc in the search area for a searcher(/searching robot) to visit that optimises the objective of maximising the probability of detection. To this end, I've been extending an existing NP-complete search problem formulation in Operations Research literature called the Optimal Searcher Path problem (OSP), in order to apply it to indoor settings which impose additional searcher movement constraints.

I've been using branch and bound to generate the paths, with one of the contributions being a bounding method that generates tighter bounds than the existing techniques (therefore speeding up the solution process) without introducing significant complexity. Naturally epsilon-optimal solutions can also be used to further trade off between search plan quality and computation time.

Ongoing work involves extending the problem to multiple searchers (getting optimal solutions for small problems and using heuristics in cases where the time window is large). A slight twist is that the the search team can involve searchers (which are capable of rescuing the victim) and scouts (which can only help to find the victim and let the searchers know where they are). Since the agents should appropriately react to exploit any newly uncovered information, fully optimising the team's actions actually requires a different solution approach.

My research interests include:

• Optimal search - particularly the optimal searcher path searcher problem applied to regions with non-uniform travel costs
• Multi-vehicle task allocation and path planning, particularly in dynamic and cluttered environments with restrictive constraints
• Robotic exploration with visibility and network connectivity constraints
• Self-localisation in active sensor networks
• Communications issues and Quality of Service in impoverished networks, including sensor networks
• Combinatorial optimisation - particularly when it applies to the action/task/path planning of multiple platforms

Upcoming Presentations

• H. Lau, T. Pratley, D. Liu, S. Huang, D. Pagac, An implementation of prioritized path planning for a large fleet of autonomous straddle carriers. Session MD:16 Resource Scheduling and Dispatching in Container Ports, International Federation of Operational Research Societies Conference (IFORS), Sandton, South Africa, 13-18 July, 2008

Recent Publications

• H. Lau, S. Huang, G. Dissanayake, Discounted MEAN bound for the Optimal Searcher Path problem with non-uniform travel times. European Journal of Operational Research (EJOR), Volume: 190, Issue: 2, Pages: 383-397, October 2008. [Abstract and details | pdf]
• H. Lau, S. Huang, and G. Dissanayake, Multi-Agent Search with Interim Positive Information. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'07), San Diego, USA, October 29-November 1 2007. [Abstract and details | pdf]
• D. Wang, N. M. Kwok, D. K. Liu, H. Lau, and G. Dissanayake, PSO-Tuned F² Method for Multi-Robot Navigation. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'07), San Diego, USA, October 29 - November 2 2007. [Abstract and details | pdf]
• H. Lau, S. Huang, and G. Dissanayake, Probabilistic Search for a Moving Target in an Indoor Environment. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'06), Beijing, China, October 2006. [Abstract and details | pdf]
• H. Lau, S. Huang, and G. Dissanayake, Optimal Search for Multiple Targets in a Built Environment. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS'05), Edmonton, Alberta, Canada, August 2005. [Abstract and details | pdf]
• G. Fang, G. Dissanayake and H. Lau, A Behaviour-Based Optimisation Strategy for Multi-Robot Exploration. IEEE Conference on Robotics, Automation and Mechatronics (RAM'04), Singapore, December 2004. [Abstract and details | pdf]
• H. Lau, Behavioural Approach for Multi-Robot Exploration. Australasian Conference on Robotics and Automation (ACRA 2003), Brisbane, December 2003. [Abstract and details | pdf]
• D. K. Liu, H. Lau and G. Dissanayake, A Hierarchical Approach and A Multilevel Genetic Algorithm for Vehicle Path Planning. 2nd International Conference on Computation Intelligence, Robotics and Autonomous Systems (CIRAS 2003), Singapore, December 2003. [Abstract and details | pdf]

Doctoral Thesis

• H. Lau, Optimal Search in Structured Environments, Doctoral Thesis, University of Technology, Sydney, 2007. Supervised by Prof. Gamini Dissanayake and Dr. Shoudong Huang. [pdf]

Seminars Given (partial list)

• Optimally Searching for a Target in Structured Environments (Operations Research Department, Naval Postgraduate School, Monterey, USA, 2/11/2007) - overview of my doctoral research on optimal search and ongoing work.
• Optimally Searching in Structured Environments (RESTS seminar, The University of Technology, Sydney, 11/05/2007) - about my thesis work.
• The Optimal Searcher Path Problem and a Branch and Bound approach (UTS-CAS seminar, The University of Technology, Sydney, 02/03/2006)
• Optimal Search for Multiple Targets in a Built Environment (Center for Robotics and Embedded Systems (CRES), University of Southern California, 26/07/2005).
• Optimal Search for Targets in a Built Environment (ISSNIP Graduate Student Workshop, University of New South Wales, Sydney, 11/05/2005).
• Military Quality of Service (MQoS) (ADI Knowledge Workshop, Garden Island, Sydney, 09/03/2004)

Videos, pictures, media, and news

Interesting videos, pictures or material for projects that I've been involved / am interested in will be posted.

• Article in Pursuit, ADI's in-house magazine, with short blurb about the ADI-UTS collaboration that I participated in. [pdf]

Academic History

• PhD (Engineering), University of Technology, Sydney, 2007.
• BEDipEngPrac (Computer Systems), University of Technology, Sydney, 2003.

Awards and Scholarships

• 2004-2006: Australian Postgraduate Award Industry (APAI)
• 2003: UTS-ADI Scholarship

Personal Pictures and Videos

Recent pictures and material - any relation to work therein is purely coincidental.

• 2006-10: Photos from IROS'06 trip to Beijing
• 2006-10: Angus the labrador!
• 2006-08: Flowers in bloom

Department Address:   

ARC Centre of Excellence for Autonomous Systems
Faculty of Engineering,
Level 6, Building 2, City Campus,
University of Technology, Sydney
PO Box 123, Broadway NSW 2007