Many industries today depend on automation and vital machinery to maintain and enhance their operations. These range from the manufacturing industry to the oil and gas industry, the pharmaceutical industry, and so on.
For instance, Industry 4.0 is considered to be the next step up in Australia’s manufacturing sector. All of these advancements are made possible due to devices like absolute rotary encoders.
Apart from the industries mentioned, these devices are also used in robotics and the CNC machines industry. That’s because they ensure the accuracy of positioning in machinery. But how do they ensure this, and what exactly are these devices?
Let’s learn more about that below.
What Are Absolute Rotary Encoders?
These encoders refer to devices that precisely map the exact position of the shafts in machinery. They also map the speed and the angular direction of the device.
Absolute encoders can also map the exact and relative position of an object after a loss of power. That’s why these devices are preferred in many industrial applications. There are two main types of absolute encoders.
What Are The Types of Absolute Encoders?
The two types of absolute encoders are:
- Single-turn absolute encoders
These absolute rotary encoders accurately measure the position of an object in a single rotation of less than or equal to 360 degrees. For instance, these encoders are used to measure the exact point at which a door will pivot.
This point helps door installers determine the angle at which the door will open and create doors accordingly. Some other applications of these encoders include being used in telescopes, antennas, and wind turbine generators.
- Multi-turn absolute encoders
Multi-turn absolute encoders are used to accurately measure the number and degree of rotation of objects. For example, they are used in servo motors, robot joints, and cranes.
We’ve spoken a lot about the fact that absolute rotary encoders in Australia accurately map the position of an object. Let’s now understand how these devices accurately map the position of an object below.
How Absolute Rotary Encoders Improve Accuracy?
Before we understand how absolute encoders improve the accuracy of objects’ position, let’s understand how they work below.
How Do Absolute Encoders Work?
Absolute encoders work in the manner indicated in the infographic below:
Let’s now understand how they improve the accuracy of object positioning below.
No Need for Homing Sequences
Absolute rotary encoders do not need to be reset or have a reference position to continue working in the event of a power loss. That’s because these devices continuously map the position, speed, and angular direction of objects.
They store these positions in their memory in the form of specific codes. So when the power supply is restored, these encoders read those codes. These codes allow them to precisely determine the object’s position just before the power goes out.
This feature makes absolute encoders more robust than incremental encoders, which require a reset or “home” position after startup. That’s why absolute rotary encoders are preferred in applications involving CNC machines or robotics.
Reliable Multi-Turn Positioning
Multi-turn absolute encoders can accurately track the shaft position of an object across multiple rotations. For instance, in many industrial applications like the shipping or logistics industry, basic operations include multiple object rotations.
This can be observed in cranes, which utilize servo motors to carry loads over a specified distance. So in the event of a power failure, the mechanical encoders remember the number of rotations and the angular position of the servo motors as well.
Their memory prevents accidents like moving the object more than required or dropping it, and so on.
In case of automation-reliant applications, multi-turn absolute rotary encoders help material handling systems function normally. Material handling systems are used to move loads over a given distance at an increased speed.
Multi-turn encoders help these systems by mapping the number of rotations of the rack and pinion systems. These systems help the systems move across long distances.
Resilience to Power Loss
Absolute encoders store position data without needing power, ensuring no loss of data during outages. This is made possible due to the types of multi-turn encoders, such as battery-operated, magnetic, and geared.
The battery-operated multi-turn rotary encoders in Australia can be used to store the position of the object during a power outage.
Magnetic multi-turn encoders store the position of the object in magnetic disks with coded patterns.
Geared multi-turn encoders store the object’s position through their primary and secondary disk rotations. These disks map the angle and number of object rotations.
High Resolution Capabilities
Many absolute encoders provide 12 to 18 bits of resolution, which translates to thousands of distinct positions per revolution. Resolution refers to the accuracy of the devices to measure the position of an object.
The resolution of an absolute rotary encoder can be determined by the following formula: 2^n. Here ‘n’ stands for the number of unique bits or positions it can map. For example, a 12-bit encoder can map 2^12 or 4096 unique object positions.
Consider the table below to check out the applications of resolutions with different encoders.
| Resolution (Bits) | Positions per Revolution | Application Example |
| 10-bit | 1,024 | Light-duty automation |
| 12-bit | 4,096 | Robotics, small machinery |
| 16-bit | 65,536 | CNC, advanced motion control |
| 18-bit | 262,144 | High-precision equipment |
As you’ve seen, absolute encoders are quite critical in maintaining the positional accuracy of given objects in various industries. Let’s consider these industries below.
Which Industries Are Absolute Encoders Used in, And How?
Consider the infographic below to learn more about the applications of absolute rotary encoders:
Wrapping Up
Absolute rotary encoders offer superior positioning accuracy, are resilient against power loss, and provide multi-turn tracking capabilities. They can be used in various industries like CNC machines, automated warehousing, and industrial robotics, to name a few.
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