Abstract: It is a key problem to improve the real time characteristics of the kernel device of a robotic controller By combining the characteristics of the robotic controller, the real time techniques of the operating system are analyzed and the differences between Linux and RTLinux are compared A scheme to improve the real time performance of the robotic controller is presented, which adopts the multi thread method to divide the robotic controller tasks into the real time tasks and the non real time tasks Finally, an example of implementing a real time device driver on RTLinux is given