• Northeastern University, P.R. China (1983a,1983b)
• Hong Kong, P. R. China (2000)
• Canberra, Australia (2001)
• USA (California, 2002, CDC 2002)
• UK(2003, Oxford,Derby,Cambridge, ECC 2003)
• Sydney, Australia (2004, UTS)
• Japan (2004, IROS 2004)
• France (2005, Toulouse)
• Spain (2005, Barcelona, ICRA 2005)
• USA (2005, Florida, ICRA 2006)
• France (2007, Annecy city, FSR 2007)