They are appearing across a host of new sectors with, for example, service robots being used to take the place of humans in areas like customer service, security, and cleaning. We’re also seeing the adoption of ‘companion’ robots that act like members of the family or even as pets.
When it comes to designing robots, they not only need to be able to move easily, but they need to be able to sense the world in which they operate.
Sensors, therefore, are used extensively to help robots react to the commands they receive and will also provide ‘feel-and-see’ features, that will help them to better understand the environment in which they are operating.
There are many types of sensors used in robotics from light sensors – such as photoresistors and photovoltaic cells - to sound sensors that can help simple robots to navigate. There are also temperature sensors, contact sensors that can trigger a robot to act accordingly and proximity sensors that can detect the presence of an object within predefined distances without any physical contact – typical examples of these kinds of sensor include IR transceivers, ultrasonic, photoresistor and pressure sensors.
There are also tilt, navigation, GPS and localisation devices, as well as those that manage voltage and current levels.
The availability of sensors that can be used in robotics has increased extensively and the type of sensor needed will be determined by what the robot is required to undertake and that could include accuracy, operating features, functionality and cost-effectiveness.
Service robots
Movement is a critical aspect of design when it comes to robotics.
“The most recent robots use a combination of motors and sensors to achieve more realistic, fluid movements and are turning to the use of high-precision TMR sensor technologies to achieve greater realism,” explained Dr. Jeroen Van Ham, Sensor Systems Portfolio TDK and who’s responsible for overseeing the company’s sensor portfolio.
“Robots that take on human duties are becoming more prevalent in various sectors, including industry, logistics, healthcare, welfare, and housing and they come in a wide variety, from automated guided vehicles (AGVs) for factories to more complex autonomous mobile robots (AMRs), customer service robots, and nursing care robots. Even ‘communication’ robots intended to entertain and provide medical care are available for the home,” said Dr Van Ham.
Industrial robots and service robots are the two main categories of robotics. Industrial robots tend to be used in factories and other manufacturing facilities to carry out specified duties in settings set apart from people.
Service robots, by contrast, work primarily in public settings and will operate near to people - such as in shops and workplaces - and carry out tasks like customer service and nursing care.
Service robot developers must always prioritise safety if robots and people are to coexist.
Increasingly, service robots are being used more widely and, according to Dr Van Ham, it’s anticipated that new kinds of robots will develop and “become more prevalent in our daily lives as sensors and systems advance.”
The role of sensors
“Sensors have a critical role to play when it comes to how robots are able to move around a room on their own and to that end, they must be able to precisely identify the surrounding environment, including the size of the space, nearby objects, and people’s movements,” explained Dr Van Ham.
To achieve this, the newest ‘companion’ robots come with a variety of sensing devices, including cameras, microphones, temperature sensors, and brightness sensors. Developing smaller, more precise, and more dependable sensors is going to be crucial if the performance of robots is to improve.
Dr Van Ham explained, “One of the more exciting types of service robots is the ‘companion’ robot. These robots are designed to lessen loneliness and reduce stress for people in settings like homes, medical facilities, and nursing homes. They can even fill the role of pets or family members. Moreover, one might almost forget they are machines
Dr Van Ham explained, “One of the more exciting types of service robots is the ‘companion’ robot. These robots are designed to lessen loneliness and reduce stress for people. Moreover, one might almost forget they are machines because of their smooth movements and the development of AI-based conversational capabilities
“Small servo motors are included in the robot’s movable body parts, including the arms, torso, and wheels, and the robot’s ability to move smoothly and naturally depends on the functionality of these motors. Here, developers are looking to achieve the optimum torque response from the motors for these small robots to operate naturally and precisely.”
Compact embedded MCUs and high-precision angle sensors, with extremely accurate angle recognition and quick response times, are essential components.
TMR sensors, which are incredibly precise and reliable, are used to measure the angle at which robotic motors rotate.
“Compared to conventional sensors, they are more accurate and can measure a rotating body’s angle, position, and other parameters over a wider temperature range,” said Dr Van Ham.
“TMR sensors, such as the TAS/TAD series, are thin-film components made up of two ferromagnetic layers sandwiching an insulator layer that is only one to two nanometres thick. They were originally developed for automotive applications, and, housed in a tiny package, provide strong noise resistance, high output, and exceptional angular accuracy and stability. As they feature two sensor elements and two discrete output systems, they also ensure a high level of redundancy,” explained Dr Van Ham.
He continued, “TMR sensors can be valuable for controlling just about anything that runs on motors. They are frequently used in high-precision magnetic detection applications, such as electric vehicles and in smartphone autofocus. However, TMR sensors also feature low power consumption, which is ideal for battery-powered applications and when combined with redundancy, they offer a compelling reason for using them in ‘companion’ service robots.”
Conclusion
As robots become increasingly common in everyday life, they need to be designed so that they can share the same environment with humans, so it’s important that the touchpoints between both are handled effectively – and it’s here that sensors will have a critical role.
If robots are to be fully integrated into the home, hospital, workplace, indeed all manner of environments, they will need to be equipped with capabilities to communicate and interact with users that are both easy to understand and to react to. That is especially important when it comes to using robots as a companion, especially when caring for the elderly, which is seen as one of the main application areas for social robotics.
While we have focused on the natural movement of robots design engineers will also have to take into account issues around communications – impaired hearing and speech in users who may be elderly will need to be considered – as well as how to ensure that users, who may have little experience with new technologies, are encouraged and helped to accept robots in their daily lives and homes.
If robots are to be accepted then it’s not just about the technology but about a better understanding and acknowledgement of issues like trust, expectations and preconceptions.
