You’ve probably heard of forklifts, salad forks, forks in the road, even forked tongues, but what do forks have to do with factory automation and object detection? I’ll get to the answer, but for now, let’s talk about arguably the most reliable form of object detection: through-beam photoelectric sensors.
An unsung hero of reliable object detection is the through-beam photoelectric sensor. Its operation is simple: an emitter sends light to a receiver. No reflectors, no fancy, high-tech lasers, and very few material limitations are involved. If the emitter and receiver are properly aligned, and within their designated range, the sensor is happy and will function well. It detects when the transmitted light is blocked.
The Achilles heel of through-beam sensors: why alignment matters
You probably have a through-beam photoelectric sensor at the bottom of your garage door. Garage door companies use this technology because it’s both reliable and inexpensive, with the power to span large distances. However, the Achilles heel of through-beam sensors is their vulnerability to misalignment. Whether it’s a complex light curtain or a simple garage door safety switch, ensuring the alignment of the emitter and receiver is key for the sensor’s reliability. Proper alignment also takes up more time during installation and may cause issues during production. Misalignment can occur whether a kid is hitting the emitter with her bike in the garage or a production worker is hanging his coat on the sensor on the factory floor.
The evolution of object detection: introducing the “fork” sensor
Imagine having the benefits of a through-beam sensor but without the hassles of installation and the risk of production disruptions. This is the key principle behind one of my favorite types of sensors designed for factories: the fork sensor. It consists of an emitter and a receiver set at a fixed distance and pre-aligned at the factory, all enclosed within a fork-shaped housing. These sensors are available in various spacings, each optimized for reliable object detection and greatly reducing the chances of errors. The beauty of this housing is that it allows for single-point mounting and provides protection for the vital parts of the sensor, preventing them from harm and being knocked out of alignment.
The use of forks in eating separates us from our ancient ancestors. We have evolved even more over the years to use different-sized forks for different courses and types of foods. Like the title of this article suggests, I can never remember which one is the salad fork. Think about the benefits of my favorite sensor type, the “fork” sensor, and see if it could make your automation process more civilized.