Sensor Technology Applied torque sensor success By Michael Steuer, global account manager at TE Connectivity G
lobally, cobots are on the rise. Within the industrial automation space alone, cobot adoption is increasing around 11 per cent year-
over-year. This is for good reason — cobots greatly enhance efficiency in the workplace. However, designing cobot components, especially robotic arms, is no small task. From operating in harsh environments and compact spaces to customized solutions, robotic arms are challenging to engineer. Typical cobot considerations include ensuring sensors maintain accurate measurements without becoming subject to torque. Arm joints usually offer limited space, which means components must be small and durable enough to withstand high repetition and torque while working. Therefore, when a major robotics company came to TE Connectivity with a big request — help optimize the design for its next generation of cobots — the engineering team knew it was up for the challenge. The design needed to meet industry-leading cobot requirements, such as high levels of functional safety, high
load-bearing capacity with increased arm speed and a lightweight design. However, the cobot still had to be compact, safe, and capable of complex functionality. In addition to regular cobot requirements, this specific application needed to prioritize temperature stability because of the motor close to the joint, subjecting it to frequent changes in
temperature. Therefore, the solution needed to minimize thermal sensitivity to maintain a high level of accuracy. How did TE Connectivity meet all these requirements? Torque sensors.
Leveraging Microfused technology A combination of torque sensors, additional connectors and cable assemblies allowed TE to design a robotic arm that met the requirements for high load- bearing capacity. However, the solution would not have been possible without Microfused technology.
Generally, TE’s torque sensor solution measures the deformation of a diaphragm under external pressure using highly sensitive silicon strain gauges in a bridge configuration. However, using Microfused technology, silicon is bonded onto stainless steel using glass. This creates a reliable and stable bond, well suited for this application’s thermoregulatory needs. The bond also transfers strain from the steel into the silicon, ensuring more accurate torque measurements over long-term use. The Microfused technology produces repeated survivability rates at 200 per cent and structural failure rates at 500 per cent of load.
www.cieonline.co.uk
Designing for dual redundancy Another essential feature of the solution was ensuring accuracy through dual redundancy. TE’s torque sensors feed two data channels through a single chip, which also has electrically segregated channels. This both preserves the integrity of the independent data outputs and enables two separate measurements from different locations on a single structure. Dual redundancy increases overall accuracy, confidence and safety.
Further improving reliability, dual redundancy also allows for cross- checking. As the cobot operates, the machine compares the independent measurements from the data channels and stops operating if the two measurements are not within a small window of variability.
By focusing on reliability and safety, TE Connectivity created a unique torque sensor solution to meet this OEM’s requirements. While developing the next generation of cobots is not a simple request, utilizing cross-functional engineering expertise moves the industry closer to a cobot future.
www.te.com Components in Electronics November 2021 39
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58
