Affected by pandemic covid-19, 2021 4th International Conference on Control, Robotics and Informatics was concerted to a virtual conference instead of being held physically in Danang, VIetnam during April 3-5 as scheduled.

The participants all showed their support and understanding in such situation, who have joined the conference and presented their papers online. On behalf of the organizing committee, we'd like to thank all the keynote speakers, invited speakers and authors. We believe we'll all survive this health crisis and get back to our normal life soon. Take care.

All accepted and registerd papers have been published into International Journal of Mechanical Engineering and Robotics Research and are freely accessible online: http://www.ijmerr.com/list-195-1.html