The increasing availability of sensors is opening up new fields of application for robots. Sensor-based control enables direct interactive control of robot movements in applications. However, features like these are only possible with robot systems capable of real-time response. Mitsubishi Electric recognised the potential of sensor-based applications early on and now offers a standard real-time control interface for all the company’s SCARA and articulated-arm robots.

Robots with vision and a sense of touch, able to respond sensitively and intelligently, are already in use in many industrial applications. Real-time control enables robots to define the path of their movement and the forces they must apply to the tools they are using during the movement process rather than before, on the basis of data returned from their sensors. The robot controller analyses the output from the sensors which can include ultrasonic, infrared and laser proximity sensors, cameras and force/torque sensors, and then plans the robot movements accordingly.
Controlling a robot in real time is only possible with the help of high-speed communication between the sensors and the controller. Mitsubishi Electric’s new CRD series of robot controllers come with a real-time PC communications interface as standard. The position data is calculated by the PC on the basis of the sensor signals and then transmitted to the robot controller at high speeds, typically in the space of 1-10 milliseconds. This real-time control capability is available in all Mitsubishi Electric SCARA and articulated-arm robots with payload ratings of 6-18kg and 3-12kg and reaches of up to 850mm and 1,385mm, respectively.
Sensor-based real-time control opens up many new applications for industrial robots. One particularly high-potential field is robot-assisted quality control where measurements and movements can now be performed simultaneously and in real time. In processes like welding, adhesive applications, deburring, drilling and milling, sensor-controlled robots can easily follow complex contours, enabling them to handle workpieces with virtually any geometry. Manual teaching of position data and movement paths is also particularly easy with this type of robot control system.
A number of Mitsubishi Electric’s long-standing partners have already been using these technologies for several years and they now offer complete systems along with measurement and analysis software packages and robot sensors.