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Robots are developed for a wide variety of uses. These include assembly, welding, monitoring marine life, rescue and recovery and even vacuuming the floor. Because of this, there is a multitude of sensors which can be implemented into the design of a robot in order for it to meet its specific needs.
Sensors are able to measure a physical quantity. They are able to convert this input into an electrical signal in order to record and monitor it. It is imperative that the right sensor is chosen based upon the robots use and the surrounding environment. Sensors that measure the same input can also differ in accuracy, precision, and sensitivity. This needs to be taken into account when designing a robot.
Sensors can measure a large array of inputs. These include environmental monitoring, distance, force, speed, pressure, temperature, magnetic flux, vibration, humidity, rotation, touch, imaging, light, biometrics, gas, acceleration, current, voltage, orientation, gravity, tilt sensing, and speech recognition.
In reality, sensors are needed in robotics in order to make them automated. Without them, a robot is, in essence, blind and deaf. Sensors allow a robot to overcome these obstacles and collect information from the surrounding environment, in order to interact with it.
Humanoid robots need a multitude of these sensors in order to mimic the capabilities of their living counterparts. Companies, such as the infamous Boston Dynamics, equip their robots with sensors that simulate sight, hearing, and touch, as well as sensors which enable the robot to understand and navigate its surroundings.
Less demanding robots, such as industrial manufacturing robots still need many different sensors in order to allow them to operate efficiently. These types of robots need to be able to pick up and move different objects without crushing or dropping them. They are therefore given torque sensors which monitor and control rotational forces.
Acoustical and piezoelectric sensors allow robots to identify prominent sounds, such as commands, in an area with background noise. Robots can incorporate preprogrammed outputs based upon the commands heard. This could be especially useful for field work, or robots in noisy environments.
The simplest sensors are switch sensors. There are three types of switch sensor; contact, limit and shaft encoder sensors. All of these sensors work without processing. The most useful type of switch sensor is the so-called “bump switch” which allows a robot to ‘feel’ when it has impacted into an object. This is a simple concept, but it can be implemented in many different types of robots.
Light sensors can also be used in multiple ways. They give a robot the ability to see. Light sensors allow robots to measure light intensity, differential intensity, and break-beam, ie the sudden reduction of intensity. These light sensors can be applied in different positions and directions depending on the robot’s intended purpose.
Sensors are important in creating robots which are efficient in their appointed purpose. The inclusion of sensors is imperative to their automation, however, developers need to take care when choosing which sensors to incorporate in the design. As stated previously, sensor type, sensitivity, accuracy, and position are all important factors for the success of the robot.
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