Tag Archives: Robotics

Shape-Changing Robot Travels Large Distances

The world of robotics is developing at a tremendous pace. We have biped robots that walk like humans do, fish robots that can swim underwater, and now we have a gliding robot that can travel large distances.

This unique and innovative robot that the engineers at the University of Washington have developed, is, in fact, a technical solution for collecting environmental data. Additionally, it is helpful in conducting atmospheric surveys as well. The astonishing part of this lightweight robotic device is that it is capable of gliding in midair without batteries.

The gliding robots cannot fly up by themselves. They ride on drones that carry them high up in the air. The drones then release them about 130 ft above the ground and they glide downwards. The design of these gliding robots is inspired by Origami, the Japanese art of folding paper to make various designs.

The highly efficient design of these gliding robots or micro-fliers as their designers call them can change shape when they are floating above the ground. As these robots or micro-fliers weigh only 400 milligrams, they are only about half the weight of a small nail.

According to their designers, the micro-fliers are very useful for environmental monitoring, as it is possible to deploy them in large numbers as wireless sensor networks monitoring the surrounding area.

To these micro-fliers, engineers have added an actuator that can operate without batteries and a controller that can initiate the alterations in its shape. They have also added a system for harvesting solar power.

When dropped from drones, the solar-powered micro-fliers change their shape dynamically as they glide down, spreading themselves as a leaf as they descend. The electromagnetic actuators built into these robots control their shape, changing them from a flat surface to a creased one.

According to their designers, using an origami shape allows the micro-fliers to change their shape, thereby opening up a new space for the design. Inspired by the geometric pattern in leaves, they have combined the Miura-ori fold of origami, with power-harvesting and miniature actuators. This has allowed the designers to make the micro-fliers mimic the flight of a leaf in midair.

As it starts to glide down, the micro-flier is in its unfolded flat state. It tumbles about like an elm leaf, moving chaotically in the wind. As it catches the sun’s rays, its actuators fold the robot, changing its airflow and allowing it to follow a more stable descent path, just like a maple leaf does. The design is highly energy efficient, there is no need for a battery, and the energy from the sun is enough.

Being lightweight, the micro-flier can travel large distances under light breeze conditions, covering distances about the size of a football field. The team showcased the functioning of the newly developed micro-flier prototypes by releasing them from drones at an altitude of about 40 meters above the ground.

During the testing, the released micro-fliers traveled nearly 98 meters after they changed their shapes dynamically. Moreover, they could successfully transmit data to Bluetooth devices that were about 60 meters away.

Cooling Machine Vision with Peltier Solutions

The industry is using machine vision for replacing manual examination, assessment, and human decision-making. For this, they are using video hardware supplemented with software systems. The technology is highly effective for inspection, quality control, wire bonding, robotics, and down-the-hole applications. Machine vision systems obtain their information by analyzing the images of specific processes or activities.

Apart from inspection systems, the industry also uses machine vision for the sophisticated detection of objects and for recognizing them. Machine vision is irreplaceable in collision avoidance systems that the next generation of autonomous vehicles, robotics, and drones are using. Recently, scientists are using machine vision in many machine learning and artificial intelligence systems, such as facial recognition.

However, for all the above to be successful, the first requirement is the machine vision must be capable of capturing images of high quality. For this, machine vision systems employ image sensors and cameras that are temperature sensitive. They require active cooling for delivering optimal image resolutions that are independent of the operating environment.

Typically, machine vision applications make use of two types of sensors—CCD or charge-coupled devices, and CMOS or complementary metal-oxide semiconductor sensors. For both, the basic functionality is to convert photons to electrons that are necessary for digital processing. Both types of sensors are sensitive to temperature, as thermal noise affects their image resolution, and thermal noise increases with the rising temperature of the sensor assembly. This depends on environmental conditions or the heat generated by the surrounding electronics, which can raise the temperature of the sensor beyond its maximum operating specification.

By rough estimation, the dark current of a sensor doubles for every 6 °C rise in temperature. By dropping the temperature by 20 °C, it is possible to reduce the noise floor by 10 dB, effectively improving the dynamic range by the same figure. When operating outdoors, the effect is more pronounced, as the temperature can easily exceed 40 °C. Solid-state Peltier coolers can prevent image quality deterioration, by reducing and maintaining the temperature of the sensor to below its maximum operating temperature, thereby helping to obtain high image resolution.

However, it is a challenge to spot cool CCD and CMOS sensors in machine vision system applications. Adding a Peltier cooling device increases the size, cost, and weight. It also adds to the complexity of the imaging system. Cooling of imaging sensors can lead to condensation on surfaces exposed to temperatures below the dew point. That is why vision systems are mainly contained within a vacuum environment that has insulated surfaces on the exterior. This prevents the build-up of condensation over time.

The temperature in the 50-60 °C range primarily affects the image quality of CCD and CMOS sensors. However, this depends on the quality of the sensor as well. For sensors in indoor applications just above ambient, a free convection heat sink with good airflow may be adequate to cool a CMOS sensor. However, this passive thermal solution may not suffice for outdoor applications. Active cooling with a Peltier cooling solution is the only option here.

Astronomical Growth of Machine Vision

Industries are witnessing rapid growth of machine vision. This technology being a vital component of the industry’s modern automation solutions, they expect the market for 3-D machine vision to nearly double in the next six years. In the manufacturing context, two major factors contribute to this increase in adoption of the machine vision technology. The first is due to the industry facing acute labor shortage problems, and the second is the dramatic decrease in hardware costs.

Additionally, with an increase in technological performance, the industry needs machine vision systems to process ever-expanding amounts of information every second. Moreover, with the advent of machine learning and advanced artificial intelligence algorithms, data collected from machine vision systems are becoming more valuable. The industry is rightly realizing the power of machine vision.

So, what exactly is machine vision? What makes a robot see? A vision system typically is a conglomeration of many parts that include the camera, lighting sources, lenses, robotic components, a computer for processing, and application-specific software.

The camera forms the eye of the system. There are many types of cameras that the industry uses for machine vision. Each type of camera is specific for a particular application need. Also, an automation solution may have many cameras with different configurations.

For instance, a static camera typically remains in a fixed position in a scenario where speed is imperative. It might have a bird’s eye view of the scene below it. On the other hand, a robotic arm may mount a dynamic camera at its end, to take a closer look at a process, thereby picking out higher details.

One of the important aspects of the vision system is its computing power. In fact, this is the brain to help the eye understand what it is seeing. Traditional machine vision systems were rather limited in their computing powers. Modern machine vision systems that take advantage of machine learning algorithms require far greater computation resources. They also depend on software libraries for augmenting their computing capabilities.

Machine vision manufacturers design these capabilities specifically for application users. They design the software to provide advanced capabilities for machine vision systems. These advanced capabilities allow users to control the tasks for the machine vision, such that they can gain valuable insights from the visual feedback.

With the industry increasingly using vision for assembly lines, the concept of a vision-guided system replacing basic human capabilities is on the upswing in a wide range of processes and applications.

One of the major applications of machine vision is inspection. As components enter the assembly line, machine vision cameras give them a thorough inspection. They look for cracks, bends, shifts, misalignment, and similar defects, which, even if minor, may lead to a quality issue later. The machine vision compares the crack, and if larger than a specified size, rejects the component automatically.

In addition to mechanical defects, machine vision is capable of detecting color variations. For instance, a color camera can detect discoloration and thereby reject faulty units.

The camera can also read product labels, serial numbers, or barcodes. This allows the identification of specific units that need tracking.

Magnetic Position Sensing in Robots

Robots often operate both autonomously and alongside humans. They greatly benefit the industrial and manufacturing sectors with their accuracy, efficiency, and convenience. By monitoring motor positions at all times, it is possible to maintain not only system control but also prevent unintentional motion, as this can cause system damage or bodily harm.

Such monitoring of motor positioning is possible to implement by contactless angle encoding. It requires a magnet mounted on the motor shaft and provides an input for a magnetic encoder. As dirt and grime do not influence the magnetic field, integrating such an arrangement onto the motor provides a compact solution. As the encoder tracking the rotating magnet provides sinusoidal and 90-degree out-of-phase components, their relationships offer quick calculations of the angular position.

As the magnet rotates on the motor shaft, many magnetic encoding technologies can offer the same end effect. For instance, Hall-effect and magnetoresistance sensors can detect the changing magnetic field. 3D linear Hall effect sensors can help with calculating angular positions, while at the same time, also offering compensations for temperature drift, device sensitivity, offset, and unbalanced input magnitudes.

Apart from signal-chain errors, the rotation of the magnet also depends on mechanical tolerances. This also determines the quality of detection of the magnetic field. A final calibration process is necessary to achieve optimal performance, which means either harmonic approximation or multipoint linearization. With calibration against mechanical error sources, it is possible for magnetic encoding to achieve high accuracy.

The driving motor may connect directly to the load, through a gearbox for increasing the applied torque, through a rack and pinion, or use a belt and screw drive for transferring energy elsewhere. As the motor shaft spins, it transfers the kinetic energy to change the mechanical position somewhere in the system. In each case, the angle of the motor shaft correlates directly to the position of the moving parts of the system. When the turns ratio is different from one, it is also necessary to track the motor rotations.

Sensorless motor controls and stepper motors do not offer feedback for the absolute position. Rather, they offer an estimate of the position on the basis of the relative change from the starting position. When there is a loss of power, it is necessary to determine the actual motor position through alternate means.

Although it is possible to obtain the highest positional accuracy through the use of optical encoders, these often require bulky enclosures for protecting the aperture and sensor from contaminants like dirt and dust. Also, it is necessary to couple the mechanical elements to the motor shaft. If the rotational speed exceeds the mechanical rating of the encoder, it can lead to irreparable damage.

No mechanical coupling is necessary in the case of magnetically sensed technologies like magnetoresistive and Hall-effect sensors, as they use a magnet mounted on the motor shaft. The permanent magnet has a magnetic field that permeates the surrounding area, allowing a wide range of freedom for placing the sensor.

New Requirements for Miniature Motors

Innovations in the field of robotics are resulting in the emergence of smarter and smaller robotic designs. Sensor technologies and vision systems use robotic applications in warehousing, medical, process automation, and security fields. Disruptive technologies are creating newer opportunities for solving unique challenges with miniature motors. These include the robotic market for efficient and safe navigation through warehouses, predictable control of surgical tools, and the necessary endurance for completing lengthy security missions.

With industries transitioning to applications requiring collaborative robotics, they need systems that are more compact, dexterous, and mobile. Tasks that earlier required handling by human hands are driving the need for miniaturized motors for mimicking both the capability and size of the hands that accomplished the work.

For instance, multiple jointed solutions representing the torso, elbow, arm, wrist, etc. require small, power-dense motors for reducing the overall weight and size. Such compact solutions not only improve usability but also improves autonomy and safety, resulting in faster reaction times due to lower inertia. Therefore, robotic grippers, exoskeleton, prosthetic arms, and humanoid robots require small, high-power density motors. Power density is the amount of power a motor generates per unit of its volume. A motor that generates greater amounts of power in a small package, has a higher power density. This is an important factor when there is a space constraint, or where a high level of output is necessary when a limited space.

Manufacturers can miniaturize motors with high power densities. Alternately, they can increase the capability of current designs. Both options are critical in reducing the space that motion elements occupy. High efficiency is necessary to obtain the maximum power possible from a given design. Here, BLDC or brushless DC motors and slot-less motor designs in combination with efficient planetary gearboxes can offer powerful solutions in small packages. Brushless solutions are flexible enough for engineering them to meet customer requirements like long and skinny designs, or short, flat, low-profile configurations.

Smooth operation and dynamic response can result in these miniature motors being dexterous and agile. Slot-less BLDC motors achieve this by eliminating detent torque, thereby providing precise dynamic motion with their lower inertia. Applications requiring high dynamics, such as pick-and-place systems and delta robots, must be able to accelerate/decelerate quickly and constantly. Coreless DC motors and stepper motors with disc magnets are suitable for applications requiring critical characteristics like high acceleration as they have very low inertia.

Ironless brushed DC motors with their high efficiency, are the best choice for battery-powered mobile applications to extend their operational life between charges. Several robotic applications now run on battery power, thereby requiring motors with high efficiency for longer running times. Other applications require high torque at low speeds, and it is possible to achieve this by matching the motor with a high-efficiency gearbox.

Some applications that are inhospitable to humans may need robot systems capable of enduring difficult environmental conditions. This may include tremendous vibration and shock. With proper motor construction, it is possible to improve their reliability and durability when operating under such conditions.

Handling Grippers

Material handling in industries is increasingly relying on grippers. Industries, ranging from automotive assembly to electronics manufacturing, all handle their materials with grippers. The increasing requirement for grippers is evident from the market being worth $100 million in North America alone today, with the number expectedly growing by 5% annually.

The sudden spurt in growth in the use of grippers can be attributed to the rise in robotics. This includes industrial robots taking on special tasks like handling increasingly complex workpieces. Designers now can take their pick from more types of grippers than before. However, even with the latest developments in robotics and gripper technology, picking the most suitable gripper for a specific application can be a daunting task.

The market today has a plethora of grippers including mechanical, adaptive, soft, magnetic, and vacuum types, with each type offering key design features and benefits. For instance, adaptive and soft grippers adapt themselves to the contours of the workpiece and are useful in various handling applications.

Mechanical grippers, both electric and pneumatic types, are popular for handling applications. Of these, the pneumatic types make up about 90% of the demand, as these tend to be lighter and more cost-effective compared to the electrical types. Being more suitable for harsh environments, pneumatic grippers have faster cycle rates and higher grip forces.

On the other hand, electric grippers offer their users better travel and force control along with greater precision. However, the presence of motors and other internal components in these grippers tends to make them heavier and increases their upfront costs.

Irrespective of being pneumatically or electrically operated, there are several design classes of mechanical grippers. For instance, parallel grippers have fingers that can pull directly apart. The most common among these is the two-finger parallel gripper. These make up more than 85% of the market for mechanical grippers. Another version is the three-finger gripper, and it can perform centering functions and handle round objects.

Other classes of mechanical grippers include the angular and radial versions. These typically have fingers that open at an angle. For instance, angular grippers open their fingers only to 30-degrees, while radial grippers can open their fingers up to 180-degrees, allowing them to handle workpieces of varying dimensions while being slower than angular grippers.

Selecting grippers for a specific application requires considering important factors. Depending on the nature of the workpiece, the designer must consider the gripping force required, the guiding strength of the jaw, and the type of the gripper itself. For instance, long gripper fingers require a long lever arm to exert greater torque on the jaws. There are flat finger designs that offer a friction-based grip for durable and bulky parts. On the other hand, handling slippery parts that require precision placement must use encapsulated designs.

Encapsulated designs have fingers with a profile shape matching the object they will handle. Usually, the fingers will be curved to hold a round object. This helps to retain the object in a specific position while preventing that part from dropping if the pressure is lost.

Meca500 – The Tiny Six-Axis Robot

Although there are plenty of robots available in the market for a myriad jobs, one of the most compact, and accurate robot is the Meca500. Launched by the Quebec based Mecademic from Montreal, the manufacturers claim it is the smallest, and most precise six-axis industrialist robot arm in the market.

According to Mecademic, users can fit Meca500 easily within an already existing equipment and consider it as an automation component, much simpler than most other industrial robots are. According to the cofounder of Mecademic, Ilian Bonev, the Meca500 is very easy to use and interfaces with the equipment through Ethernet. With a fully integrated control system within its base, users will find the Meca500 more compact than other similar offerings are in the market.

Mecademic has designed, developed, and manufactured several compact and accurate six-axis industrial robot arms on the market. Meca500 is one of their latest products, the first of a new category of small industrial robots, smaller than most others are, and ultra-compact.

The first product from Mecademic was DexTar, an affordable, dual-arm academic robot. DexTar is popular in universities in the USA, France, and Canada. Although Mecademic still produces and supports DexTar on special request, they now focus exclusively on industrial robots, delivering high precision, small robot arms. With their academic origins, Mecademic has retained the predilection of their passion for creativity and innovation, and for sharing their knowledge.

With the production of Meca500, a multipurpose industrial robot, Mecademic has stepped into Industry 4.0, and earned for itself a place in the highly automated and non-standard automated industry. With Meca500, Mecademic offers a robotic system that expands the horizons for additional possibilities of automation, as users can control the robot from their phone or tablet.

This exciting new robotic system from Mecademic, the Meca500 features an extremely small size, only half as small as the size of the smallest industrial robot presently available in the market. Meca500 is very compact, as the controller is integrated within its base and there is no teaching pendant. The precision and path accuracy of the robot is less than 5 microns, and it is capable of doing the most complex tasks with ease.

Applications for Meca500 can only be limited by the users’ imagination. For instance, present applications for the tiny robot include a wide range, such as animal microsurgery, pick and place, testing and inspection, and precision assembly.

Several industry sectors are currently using Meca500. These include entertainment, aeronautics, cosmetics, automotive, pharmaceuticals and health, watchmaking, and electronics. Users can integrate the compact robot within any environment, such as their existing production line or even as stand-alone system in their laboratories.

The new category of robots from Mecademic is already smaller, more compact, and more precise than other robots are in the market. Mecademic’s plans for the future include offering more space saving, more accurate, and easier to integrate industrial robots. They envisage this will enable new applications, new discoveries, new products, new medical treatments, and many more. Their plan is now to build a greater range of compact precision robots while becoming a leading manufacturer of industrial robots.

Robotics and Motion Control

Across the industrial space, automation is a growing trend in factory floors throughout the world. This is essential to improve the efficiency and production rates. When creating the automated factory, engineers may introduce a robotic system or implement a motion control system. Although both can essentially accomplish the same task, they have their own unique setups, motion flexibility, programming options, and economic benefits.

The Basics

A straightforward concept, motion control initiates and controls the movement of a load, thereby performing work. A motion control system is capable of precise control of torque, position, and speed. Motion control systems are typically useful in applications involving rapid start and stop of motion, synchronization of separate elements, or positioning of a product.

Motion control systems involve the prime mover or motor, the drive, and its controller. While the controller plans the trajectory, it sends low-voltage command signals to the drive, which in turn applies the necessary voltage and current to the motor, resulting in the desired motion.

An example of a motion control system is the programmable logic controller (PLC), which is both noise-free and inexpensive. PLCs use the staple form of ladder-logic programming, but the newer models also have human-machine-interface panels. The HMI panels offer visual representations of programming the machine. With PLCs, the industry is able to control logic on machinery along with control of multiple motion-control setups.

Robots are reprogrammable, multifunctional manipulators that can move material, tools, parts, or specialized objects. They can be programmed for variable motion for the benefit of performing a variety of tasks.

Most components making up the motion control system are also a permanent part of robots. For instance, a part of the robot’s makeup includes mechanical links, actuators, and motor speed control. The robot also has a controller, which allows different parts of the robot to operate together with the help of the program code running in the controller. Most modern robots operate on HMI that use operating systems such as Linux. Typical industrial robots take many forms such as parallel picker, SCARA, spherical, cylindrical, Cartesian, or a simple articulated robotic arm.

Robot systems also make use of drives or motors to move links into designated positions. Links form the sections between joints, and robots can use pneumatic, electric, or hydraulic drives to achieve the required movement. A robot receives feedback from the environment from sensors, which collect information and transmit it to the controller.

The Differences

While the robot is an expensive arrangement, a motion control system has components that are modular, and offer greater control over cost. However, motion controller components require individual programming to operate, and that puts a greater knowledge demand on the user.

Motion control systems, being modular, offer the scope to mix and match old hardware with the new. This facilitates multiple setups, with modular configuration ability, and applicable cost constraints.

With hardware differences between products decreasing rapidly, purchasing decisions are now mostly based on the software of the system. For instance, most modern systems are plug-n-play type, and they rely more on their software for compatibility.

How Good are Cobots at Welding?

The manufacturing industry has been using robots widely for several years as a replacement for the human laborer. Recent advances in this field are the Cobots or collaborative robots. They are called collaborative as their design makes them work alongside an individual as a part of a team rather than replacing the humans.

Cobots are good at operations and activities that cannot be fully automated. However, the process speed does not improve for activities such as workers ferrying parts backwards and forwards between themselves on the assembly line with the robots locked away in cages.

Manufacturers such as Ford are already on the cobot bandwagon, and the new robots could transform the way the industry works. The Ford factory has collaborative robots installing shock absorbers on vehicles on the production line along with humans. The cobots work with accuracy and precision, boosting the human productivity, while saving them valuable time and money.

At present, the industry uses four main types of cobots. They are the Safety Monitored Stop, Speed and Separation Monitoring, Hand Guiding, and Power and Force Limiting.

The Safety Monitored Stop is a collaborative feature used when the cobot works on its own, but sometimes needing assistance from an operator. For instance, in an automated assembly process, the worker may need to step in and perform an operation on a part that the cobot is holding. As soon as the cobot senses the presence of the human within its workspace, it will cease all motion until the worker leaves the predetermined safety zone. The cobot resumes its activities only after receiving a signal from its operator.

Speed and Separation Monitoring is similar to the Safety Monitored Stop, with the cobot operating in a predetermined safety zone. However, this cobot’s reaction to humans is different. The Cobot will not automatically stop because of the human presence, but will slow down until its vision detection system informs it of the location of the person or object. The Cobot stops only if the person is within a predetermined area, and waits for the proximity to increase before resuming its operations. This cobot is useful in areas with several workers are present, at it requires far fewer human interventions.

Although a Hand Guiding cobot works just as a regular industrial robot does, it has additional pressure sensors on its arm device. The operator can therefore teach the cobot to hold an object hard enough and to move it fast enough without damaging the object, while securely working with it. Production lines that handle delicate components find Hand Guide cobots very useful for careful assembly.

Power and Force Limiting cobots are among the most worker-friendly machines. They can sense unnatural forces in their path, such as humans or similar objects. Their joints are programmed to stop all movement at such encounters, and even reverse the movement.

As many skilled workers retire, and replacements are rare, the American Welding Society is working with Universal Robots, to produce a new attachment to their UR+ line of cobots with welding capabilities. The robot moves along the start and stop path of the desired weld, and welds only the specified stitch areas.

What is an i-Robot?

The level of CO2 in our atmosphere is increasing at alarming levels, affecting all life on Earth either directly or indirectly. For instance, it is related to global warming risks, reducing the quantity of ice in the polar regions, which in turn changes the level of seas all around as the ice melts. This has significant consequences on several human activities such as fishing. It also affects the submarine environment adversely, together with the associated biological sphere. For long, scientists have been monitoring the marine environment and studying the status of the seas.

However, the harshness of the marine environment and/or the remoteness of the location preclude many explorations under the sear by vehicles driven by the mother ship. Scientists are of the view robots could effectively contribute to such challenging explorations. This view has led to the development of Autonomous Underwater Vehicles or AUVs.

One such AUV is the Semi-Autonomous Underwater Vehicle for Intervention Mission or SAUVIM, and is expected to address challenging tasks as above. The specialty of SAUVIM is its capability of autonomous manipulation underwater. As it has no human occupants and no physical links with its controller, SAUVIM can venture into dangerous regions such as classified areas, or retrieve hazardous objects from deep within the oceans.

This milestone is a technological challenge, as it gives the robotic system the capability to perform intervention tasks such as physical contact with unstructured environment but without a human supervisor constantly guiding it.

SAUVIM, being a semi-autonomous vehicle, integrates electronic circuitry capable of withstanding the enormous pressure deep ocean waters generate. In general, it can operate in the harsh environmental conditions—low temperatures of the deep oceans—in a reliable and safe manner. Ensuring the effectiveness of such robots requires a high level of design and accurate choice of components.

As SAUVIM operates semi-autonomously, it needs huge energy autonomy. For this, Steatite, Worcestershire, UK, has introduced a new solution in the form of long-life batteries, ones capable of operating in submarine environment. These Lithium-Sulfur (Li-S) battery packs, a result of the first phase of a 24-month project, improves the endurance and speed of autonomous underwater vehicles when deep diving.

Primary advantages that Li-S batteries offer are enhanced energy storage capability to provide improvements in operational duration, despite being constructed from low-cost building materials.

The National Oceanography Center in Southampton, UK, completed the first phase of the Li-S battery project, after repeatedly testing the cells at pressure and temperatures prevailing in undersea depths of 6 Kms. According to the tests, Li-S cells can deliver performances similar to those at ambient conditions, while their effective Neutral Buoyancy Energy Density or NBED is almost double that offered by Li-ion cells used as reference. Life tests, performed on a number of Li-S cells demonstrate they can reach over 60 cycles with slow discharge, and 80 cycles with fast discharges.

The energy within an AUV is limited, which also limits its endurance. Therefore, to conserve the available energy, speeds of AUV are usually kept low at 2-4 knots. Therefore, to enhance or expand this operational envelope, it is necessary to increase the energy available within the vehicle, and the Li-S batteries do just that to increase the vehicles range and speed.