In addition to the sensors identified in Part 1 of this blog, there are several others required for different types of robots.
Chemical, light and color sensors enable the robot to evaluate, adjust and detect problems with its environment.
For humanoid robots that can walk, run or even dance (like Dobi, made by Chinese company WL Intelligent Technology), stability is a major issue. But the same types of sensors are needed, just as they are in smartphones, to provide accurate location data for any untethered robot. For these applications, 9 degrees of freedom (9DOF) sensors or inertial measurement units (IMUs) with 3-axis accelerometers, 3-axis gyroscopes and 3-axis magnetometers provide the required measurements. If location in the horizontal direction is required, a pressure sensor to provide altitude can be added. Pressure sensors can also be used for tactile measurements to ensure the right amount of force is exerted by hands or grippers.
In addition to established industrial applications in material handling and specialized processes such as welding, general purpose applications in assembly lines provide numerous opportunities for robots with the right types of sensors (such as rotational or linear speed, proximity, color, distance and more) to improve line speed and achieve higher quality control.
First responder robots that can avoid the need for human presence in hazardous or dangerous situations can add a variety of sensors, especially to detect the presence of chemical or biohazards
Besides normal industrial type applications, robots are finding many uses in farming and agriculture. These applications can also take advantage of several chemical sensors for highly accurate measurements and controlled dispensing of materials.
One report, predicts that the global industrial robot sensors market will grow steadily at a compound annual growth rate (CAGR) of about 8% by 2021. For a broad range of robotic sensing applications, including consumer and automotive, another report specifically says vision systems alone will be a market of $5.7 billion by 2027 and force sensing will reach over $6.9 billion.