Ultra-Compact Optical Kit Encoders for Surgical Robots

Optical kit encoders help surgical robots to achieve highly precise control over movements, rotations, and positioning. For such sophisticated applications Lika Electronic has developed a full line-up of high precision optical kit encoders in an ultra-compact modular design.
They ideally suit the needs of the full kinematic chain on a robot arm and fit the sequence of joints, from shoulder to end effectors (grippers, needles, or other tools).

AMM is a PCB-based series of rotary absolute encoders. They are designed in a range of shaft diameters ranging from 45 mm down to 6 mm (1.771” ÷ 0.236”) for direct integration into sequential joints of robotic arms. They excel in small size, low profile, minimum weight, high resolution, and the finest accuracy. They can be customized to fit virtually any package and meet specific installation requirements. The construction is frameless and bearingless, i.e. they are not equipped with shaft, bearings, flange, and housing. Rotor and stator have no moving parts, so they are wear-free and work together without making contact. The risk of failures due to vibration, shocks or mechanical stresses is limited; while the lack of wear eliminates machine downtimes and maintenance. Less mechanical components allow to reduce the overall footprint and the weight of the encoders as well as their cost. They rely on optical measuring principle and do not suffer magnetic interferences. They are the best choice for high-dynamics and demanding positioning applications due to very high resolution and accuracy. All encoders are equipped with LEDs for diagnostic information.


AMM80 is compact, slim, and frameless and has a large through hollow shaft that fits diameters up to 45 mm / 1.771”. It can be installed easily and quickly thanks to the pilot flange or the two precision pins and does not need calibration. 

It provides position feedback via SSI, BiSS C-mode, and RS-485 interfaces. It can be singleturn and multiturn. The resolution is up to 23 bit singleturn (8,388,608 cpr) and 16 bit multiturn (65,536 rev.), the accuracy is ±0.010°.
An additional incremental track offers 1,024 Sine/Cosine 1Vpp signals for speed feedback and interpolation needs.


AMM5A comes in a very compact and flat frameless package (thickness is less than 15 mm / 0.59”) and is ideally suited for installation in constricted spaces.
The hollow shaft offers a large internal diameter (24 mm / 0.945" through hollow bore) and enables contactless mechanics without integral bearings, thus it is unaffected by wear, friction, fatigue, and mechanical stresses. 
AMM5A encoder can be both singleturn and multiturn. Singleturn resolution can be 17 bits (131,072 cpr) to 23 bits (8,388,608 cpr). In multiturn versions, the number of revolutions is 65,536. It further provides additional Sine/Cosine 1Vpp signals for speed feedback (512 sinusoidal signals per revolution).


AMM36 combines high resolution and precision with compact size and minimum weight.
It is perfect for the smallest robotic joints and for rotary end effectors. It has a diameter of 35 mm / 1.378” and a thickness of 18 mm / 0.708”; the weight is reduced to a few dozens of grams.
It can be installed on 6-mm / 0.236” diameter shafts and does not need any calibration procedure.
AMM36 is available in both singleturn and multiturn versions. It offers a singleturn resolution up to 22 bits (4,194,304 cpr) and up to 65,536 revolutions and provides the position information via SSI, BiSS C-mode and RS-485 interfaces. It also produces additional Sine/Cosine 1Vpp signals (256 sinusoidal signals per revolution) for speed feedback.


To control the linear movements on end-of-arm tooling of robotic arms (such as on needles) Lika Electronic has developed the SOA1 kit encoder.
SOA1 is a PCB-based linear absolute encoder designed to control the micro-movements of robot end effectors at sub-micrometer scale.
It relies on optical sensing technology and must be paired with a linear scale.
The measuring length is 500 mm (19.685”), other lengths are available on request. Its operation is non contact and there are no components subject to wear and fatigue.

Lika Electronic has long-standing experience in the encoders and position measurement industry and can develop customer-specific solutions that meet individual size, shape, shaft diameter, resolution, interface, connection, and operational environment needs.
For more information please contact our Sales team.