Innovative Motion Solutions Fuel Latest Robotics Trends

INTRODUCTION

Robotic innovations are being fueled by developments in automation and Artificial intelligence (AI), which opens up new markets that require the creation of smaller, more intelligent robotic designs. The motion control system is a crucial component of these designs, providing the power behind robotic applications and facilitating the required compact size, effectiveness, and precision. This paper covers the latest trends in three popular applications – bionics

BIONICS

Bionics Overview

The word bionics is a blend of two words: biology and electronics. First coined in 1958 by Jack Steel, the term became mainstream in the 1970s through the popular television series The Six Million Dollar Man and The Bionic Woman. However, the bionics of today don’t merely exist on the screen, having shifted out of the entertainment realm and into the world of medical devices. Current bionic solutions focus on enhancing the lives of those with disabilities to help them improve their movement and mobility. Two of the most common examples are prosthetics and exoskeletons.

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Prosthetics include battery-powered bionic limbs (typically hand, wrist, elbow, or knee) driven by small DC motors. The prosthetic can be controlled by either a myoelectrical signal that uses impulses from the residual limb or a microprocessor that collects position and acceleration data from sensors to determine proper motion.

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Exoskeletons are wearable devices that provide external support to the body and typically involve the limbs. These devices assist the patient either through an electrically powered mechanism or an unpowered mechanical configuration; they are often employed to enhance patient strength, endurance, and mobility. Exoskeletons assist people with disabilities to walk or perform tasks that were otherwise impossible before the development of this technology.

Miniature Motors in Bionics Applications

Due to the sensitive nature of the application, the miniature motors powering these devices must be compact, lightweight, highly precise, and facilitate long battery life. Bionic systems work best with brush DC coreless and Ultra ECTM brushless slotless motors; small brush DC motors are typically utilized in elbow or finger applications, while flat BLDC motors are used for the larger joints such as the hip knee, or shoulder. These motors can be combined with planetary gearheads to adjust motor speed, increase torque, and optimize system power, or combined with encoders to provide accurate joint position feedback, correlate the precise open/closure measurements, and coordinate specific grip patterns.

Current Trends in Bionics

The weight of a prosthetic or exoskeleton must be light and robust enough to handle the specifically designed tasks. Advances in materials such as carbon fiber and graphene help minimize the overall weight, while lightweight, highpower density motors and gearmotors provide the necessary durability.

Technology advancements in control systems and ergonomics have led to a more intuitive and comfortable user operation. Lightweight, high-power density motors decrease the overall device weight to allow the user more easy and natural movement. Motors with high dynamic response contribute to smoother operation, reliable grip patterns, and increased strength.

New innovations and improved manufacturing technologies help drive down costs to make bionic devices more affordable. 3D printing ability allows device developers to quickly test new ideas to reduce development time. In addition, increased manufacturer collaboration with motion control experts helps optimize motor performance, which leads to more cost-effective actuation systems.

Research is already underway to develop brain-machine interfaces that will allow users to control bionic limbs with their thoughts, while development over the next decade is expected to make bionic limbs even more intuitive and responsive.

SURGICAL ROBOTICS

Surgical Robotics Overview

The field of robotic surgery has expanded dramatically over the past few decades to encompass a long list of procedures that can be safely performed today. The first robot-assisted surgery occurred in 1985, with only modest improvements in capabilities until 2010, when the DaVinci system became the most prevalent surgical robot in the field.

Surgical robots are typically a combination of various surgical tools and robotic arms that are equipped with laparoscopic clamps. Surgeons can precisely control the robotic arms from a remote console. The robotic arms and tools provide haptic feedback that gives the surgeon a similar sensory response to an in-person surgical procedure, while their extreme precision facilitates minimally invasive surgery, allowing the patient to recover much faster than with traditional open surgery.

Miniature Motors in Surgical Robotic Applications

Surgical robot applications have unique requirements; these include compact size, low weight, high power density, and sterilization capabilities. Because of the high degree of variability in application demands, it is impractical to create a onesize- fits-all motor solution. Notably, not all motors within a surgical robotic system require a sterilizable solution. Other requirements may focus on the robustness and durability of the motor, such as in autoclave applications, or precise positioning needed for robotic motion control, such as joint manipulation.

Multiple miniature motor technologies can power surgical robots, including brushless DC, coreless and iron core Brush DC, and linear stepper motors. Motor customization ensures that the desired performance goals are met within a defined package size. Specific examples of surgical robotics applications that utilize miniature motors include:

•	Endo-Wrist
•	Tool Insertion
•	Arm Rotation, Yaw, Pitch, Holding
•	Haptic Feedback
•	Vision System
•	Traditional Surgical tools

Current Trends in Surgical Robotics

The global market for surgical robotics has grown significantly during the past decade. The market size, valued at USD 4.4 billion in 2022, is projected to grow at 18% CAGR through 2030. Technical innovations, advances in computational capabilities, and improvements in vision systems have and will continue to drive this growth. Improvements in robotic platforms, surgical instruments, imaging systems, haptic feedback, and artificial intelligence enhance the precision and capabilities of robotic-assisted surgeries.

A factor in the continued expansion of robotic surgery is the wide global adoption of this technology by healthcare institutions and surgeons to improve surgical precision, reduce invasiveness and recovery times, and enhance patient outcomes.

The use of AI and machine learning algorithms to analyze medical data and assist in surgical decision-making will become more common over the next decade to improve surgical outcomes and reduce the risk of complications. Advances in teleoperation technology may also allow surgeons to remotely perform complex surgeries on patients who are in remote or inaccessible locations.

END EFFECTORS

Overview of End Effectors

Robotics, by nature of the tasks they perform, simulate repetitive actions traditionally performed by humans. Almost every robotic application needs a device to pick up or grip an object, hold a tool, or push/pull an object. End effectors, found at the end of robotic arms, perform the required actions associated with a specific robot and are available in several configurations; these include parallel, angular, and three-finger electrical grippers.

•	Parallel Electric Grippers are the most common type of electrical end effector, consisting of two jaws that move in parallel to each other to grasp an object. These grippers are versatile and can handle a wide range of object sizes.
•	Angular Electric Grippers have jaws that move in an angular motion, typically with rotation around a central pivot point, and are suitable for applications where objects need to be picked up from the side or at an angle.
•	Three-Finger Electric Grippers feature three individually controllable fingers that can adapt to objects of different shapes and sizes. These grippers offer increased dexterity and the ability to handle complex objects.

Miniature Motors in End Effectors

Miniature electric motors are preferred over traditional pneumatic devices due to motor controllability, versatility, power density, and robustness. They are responsible for powering these devices, thus ensuring the execution of highly precise gripper finger positioning, gripping detection, and control of the gripping force and speed.

Both brush DC and BLDC motors are commonly employed in these applications. Brushless slotless DC motors offer the high-power density, low inertia, high precision, and low weight needed to meet application requirements. Encoders are incorporated into gripper designs to provide feedback on the gripper jaws, while gearheads can also be used to optimize the power point (speed, torque) required for the application. Motor customization is also important; customization examples include adding multiple windings and gearboxes to tailor speed and torque, as well as employing special materials to withstand shock, highduty cycles, and temperature constraints.

Current Trends in End Effectors

High torque, power-dense motors provide the required grip force. Future gripper designs will push manufacturers to develop higher motor torque and power density for improved grip force and compact and lightweight gripper designs. The increased need for precise control of position and force will require motors with advanced feedback devices, such as high-resolution encoders, to enable accurate and responsive grip adjustments. Improved dynamic response of the gripper motors ensures optimal handling of objects of different sizes, shapes, and weights.

Improved responsiveness contributes to quicker open and close times that drive higher productivity. This trend will favor motors with improved acceleration capabilities.

Grippers are subjected to repetitive and sometimes demanding operating conditions. Future trends to incorporate robots into hazardous and environmentally challenging applications will require electric motors to be robust, durable, and reliable. Motors must be able to withstand continuous use over extended periods without significant performance degradation. Improved motor designs and materials can contribute to enhanced longevity and reliability.

Overall system cost reduction is another trend that many end effector manufacturers face. Electric grippers will continue to replace traditional pneumatic grippers that require complex air supply systems, such as compressors, filters, regulators, and valves. The replacement of these pneumatic components with electric grippers will help reduce the costs associated with installing, maintaining, and operating pneumatic systems. As the demand for energy-saving solutions increases, future electric gripper systems will need to prioritize energy efficiency. Future motors will be designed to reduce energy losses and minimize power consumption during gripping operations. Energy-efficient designs will also contribute to a reduced cost of ownership.

Over the next decade, the integration of machine vision and AI will allow grippers to identify and manipulate objects more accurately, even in cluttered or complex environments. To increase end-effector efficiency and versatility, future developments in the design of grippers should allow them to perform multiple tasks simultaneously.

CONCLUSION

Miniature motors are uniquely suited to solve challenges within the robotics industry due to their compact package size and incredible performance capabilities. These motors are optimized to meet – and exceed – the most challenging application requirements, be this by powering bionic limbs to increase patient mobility and independence, enabling surgical robotic technology to improve patient recovery time and minimize hospital stays, or improving gripper technologies to reduce the need for dangerous/repetitive human tasks in unsafe worker environments.

Portescap’s multi-technology offerings and collaboration expertise are big advantages for customers - providing several technology choices for an application, each offering specific advantages in meeting critical requirements. Portescap’s engineering experts have decades of experience in solving the most challenging motion applications, leading to uniquely tailored, cost-effective, robotic solutions.

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