I love learning about manufacturing, which is why I am always checking out those shows that describe how different things are made. However, a friend of mine mentioned that it could be really helpful to actually do a little more research to find out how products are made in different places as well. I started focusing on learning, and it was cool to see just how many different options there were out there. As I explored the world of manufacturing, a friend of mine also got interested in the process, and encouraged me to make this blog. Find out more about making better products each and every day.
When you are designing a control system, an important component of the control system is whether it is a closed or open-loop system. Both types of systems are fundamentally different and you will need to know which is the best for your industrial application.
Open-Loop Systems and Human Input
With an open-loop system, the behavior of the system is based entirely on an input. The output has no impact on the control action. Open-loop systems require human input at some point. Open-loop systems tend to be less expensive initially until the long-term cost of labor has been factored in. If the output does not change very often, an open-loop system can be more affordable. Also, when a process disturbance is erratic or when a process disturbance is very rare, an open-loop system is a better choice.
Closed-Loop Automation
With a closed-loop system, the output affects the behavior of the control system. The control system modifies the output to create a desired outcome. A closed-loop system is fully automated. A closed-loop system can the be right choice when you are able to rely on measurements and do not need a human input to make corrections. The processes need to have a degree of predictability to where a human doesn't need to correct the process.
Error Signals
The closed loop system takes the desired output and compares it to the actual output. When there is a deviation between the desired output and the actual output, this generates an error signal. For example, if a device must heat a product to a particular temperature, but the measured temperature is lower than the desired temperature, a closed-loop system would produce an error signal and would then raise the temperature until it reaches a desired temperature. With an open-loop system, a human would need to observe the temperature deviation and correct it.
The Importance of Maintenance
For the closed-loop system to be functioning properly, all components must be tested to determine that they are functioning properly. For example, a sticking gear needs to be replaced with a gear that functions properly. Any transportation time needs to be minimized.
Advantages of Closed-Loop Systems
A well-designed closed-loop system can be expensive to implement, but it is less expensive in the long-run than a closed-loop system because it does not require the human labor needed to maintain the system. Unstable processes can be stabilized without the need for human input.
For more information, reach out to companies like Solutions Engineering.