One of the easiest ways to connect a legacy asset to your digital platform is by installing sensors on the machine--and here are a few that you might consider for your factory floor.
One of the most cost-efficient ways of connecting legacy assets to a factory’s digital platform is by attaching Internet of Things (IoT) sensors on the machines. These devices, enabled to gather and transmit performance data from the machines, can unlock vital information that can extend the usefulness of the machines.
Modern smart sensors can transmit data to the edge of the cloud where it can be processed and analyzed by digital technologies. There are several categories of sensor that can be deployed in these scenarios.
Proximity
These sensors are used to detect an obstacle before bumping into it, measure distance, detect if a part is in the right position, and model an environment in 2D or 3D. They can be deployed on robots, automated production lines and conveyor systems, among others.
Types of proximity sensors include inductive sensors, lasers, cameras, ultrasonic and photoelectric sensors. Some of the top companies are SICK, Panasonic and ST Microelectronics.
Temperature and Humidity
Mechanical devices tend to generate lots of heat when they operate and that heat can be a useful and accurate indicator of the machine’s functioning. Temperature sensors can help detect machine wear and tear, damage and overheating–and help prevent failure and damage. Temperature sensors are often paired with humidity sensors; high temperature in the presence of water can create vapor that increases humidity.
These sensors are used in assembly line to monitor temperature and humidity in order to prevent overheating and breakdowns, in addition to tracking overall temperature in the factory–and are particularly useful in manufacturing processes that use heat to make products or have electronics that can be damaged by high humidity.
Wireless sensors are becoming increasingly popular in industry.
There are a variety of different sensors for the specific medium and environment. Common sensor types are thermometers, infrared sensors, thermocouples, thermistors and resistant temperature detectors (RTDs). Leading companies that produce temperature and humidity sensors include Texas Instruments, Honeywell and Sensata Technologies.
Vibration
These sensors detect and monitor the frequency and magnitude of vibrations emanating from individual components, whole machines or entire systems. Vibration sensors can be connected directly to an asset or monitor it wirelessly and usually generate data on vibration frequency and intensity. By tracking when vibration spikes happen and how strong they are, operators can determine root causes of a machine’s impaired performance. And these sensors don’t just track vibration on spinning components–they can also be used to monitor conveyors, panels and other machine parts.
Like the temperature and humidity sensors, they provide valuable machine performance data that empowers maintenance personnel with information to predict machinery maintenance–and avoid equipment failure that costs both time and money to address.
Types of vibration sensors include meters, gyroscopes, strain gauges, accelerometers, microphones, Eddy-Current sensors and laser displacement sensors. Bosch, Honeywell and SKF are market leaders in this field.
Pressure
Pressure sensors monitor machine components that manipulate water, gas or other fluids and liquid chemicals–often at high pressures. The sensors can be arranged to warn the factory operators, digital or human, when low or high limits are being reached or exceeded.
Generating high pressures can be dangerous and can cause significant wear and damage to machines. The data generated by these sensors can be analyzed to detect when pressure is reaching dangerous levels, enabling the factory’s system to shut down or modify the manufacturing process automatically and alert factory staff.
The most common pressure sensors are turned parts and vacuum sensors; these devices can not only detect high pressures, they can also monitor other factors such as fluid and gas flow efficiency, speed, water levels, and whether the pressure drops below the atmospheric pressure level of the surrounding environment. ABB, Siemens and Honeywell are among the market leaders in this sector.
Torque
Torque sensors are used to measure, as the name suggests, the torque force generated by high speed motors and its effect on the rest of the machine. That force is even more significant when the machine is under a heavy load. These sensors are positioned to monitor a motor or shaft in the legacy machine and can provide valuable insights to help shop floor operators maintain quality, reduce machine wear and take preventative maintenance actions to keep the asset in top form.
This type of sensor can be used at any step along a manufacturing line to provide extra protection when a machine takes a load. As an added benefit, the sensor data can be used to determine a machine’s fail point with greater accuracy–making it possible not only to determine a machine’s optimal load, but also to raise its overload capacity to increase its productivity. And as noted with other sensors above, the data can be used by operators to predict failures and perform preventative maintenance.
The two most common torque sensors are rotating torque sensors and torque transducers. Crane Electronics, HBK Benelux and Honeywell.
Multi-Function Sensors
A sensor’s utility increases significantly when it can monitor several variables at once. Tri-axial accelerometers are one type of those sensors: they can monitor and measure variables that include vibration, displacement, acceleration and velocity on the many rotating and turning parts of a factory machine.
Another type of multi-function sensor seeing increased use are the micro-electromechanical systems (MEM). MEMS are miniaturized solid-state electronic sensors with built-in semiconductors. They are used to detect motion–in particular, whether a component is out of alignment–and trigger an action from a machine to realign the component. More complex versions of the sensors can also monitor tilt, acceleration and gravity, which is especially useful for operations conducted by high-precision CNC machinery.
Video: https://youtu.be/N2dhZFDtfWU
SICK sensors are deployed to collect data in the aluminum industry.
Examples
The operator of a legacy CNC (Computerized Numerical Control) could deploy a suite of sensors to connect the asset to a digital platform. These sensors include an accelerometer to monitor vibrations to ensure the machine’s rotation is in proper alignment; an RTD to track the temperature of the tool and material being worked on; a camera to detect and verify that components are in the right position; and a torque sensor to monitor how the machine is handling its load.
For a legacy robotic arm, many of the same sensors could be implemented: a vibration sensor to monitor the machine’s mechanical performance, a temperature sensor to check if the arm is overheating, and a camera to ensure it carries out its movements properly. In addition, a proximity sensor could be installed to monitor the robot’s movement and warn of any obstacles or collisions.
Converting an assembly line into a smart assembly line could require torque sensors to track the load of the assembly line’s components, vibration sensors to monitor not only the vibrations of the machines but the speed of their processes, proximity sensors to help ensure the components are moving as they should and avoid collisions, and cameras to oversee that each step of the assembly line is being done properly. Depending on the product being assembled, temperature and humidity sensors could also be deployed.
More and more facilities are adopting IoT technologies every day–and there’s increasing pressure for operators of legacy assets to bring those valuable machines into the digital world to remain competitive. Thanks to the development of sensors like the ones listed above, it is becoming easier and cheaper to do exactly that–and extend and even enhance the usefulness and operating life of those legacy assets.
