maxon motor unveils the world’s smallest inductive encoder.
Small, robust and accurate, maxon motor’s inductive micro encoder is a milestone in encoder technology. Secure against the effects of EMC, dust or oil, it has a configurable index pulse and integrated commutation signals. And its diameter is just 6mm.
The general basis of inductive encoders is that the inductance of one or more coils changes in relation to the material used. For example, a semi-circular iron core representing the material measure could be directed to a coil which then changes its inductance. However, there are drawbacks to simple inductive encoders, such as the temperature dependence of the soft iron/ferrite. External magnetic fields can also change the permeability of the material used, well below saturation point.
This is why highly accurate inductive encoders are ironless. The contrast is generated with eddy currents. These encoders have long been featured in large motors, but have not been produced for micromotors until now. maxon motor has invested heavily in the development of these greatly miniaturised inductive encoders. The result is the MILE, an inductive encoder where the contrast is generated with eddy currents. maxon’s Inductive Little Encoder is the smallest of its kind in the world.
The new MILE encoder delivers 64 pulses at up to 120,000 rpm, has 3 channels, line driver and integrated commutation outputs. Typical areas of application are medical technology, robotics and industrial applications in harsh environments. The MILE is available in combination with the EC6 brushless DC motor, extending the length of the combination by only 1mm. Other combinations with large motors will follow.
Built for eternity.
In the eighth year of its Mars expedition, the Mars rover Opportunity has found evidence that water once existed on Mars. According to briefings by NASA, in late 2011 the rover found a vein of a notably light coloured mineral – apparently gypsum – deposited by flowing water.
For scientists, the gypsum deposits found by Opportunity on Mars are a sensation. They are convinced that the discovery proves that water once flowed at this site. On its way through the desolate Meridiani plane, the rover came across the light coloured streaks in the ground by chance. An analysis of the minerals should help scientists better understand the geological history of Mars. Billions of years ago, the atmosphere on Mars was significantly denser; evidence indicates that there was once water in abundance on the surface of the planet. Today, the atmosphere is too thin to allow water to exist in liquid form.
The deposits formed at the same point on Mars where they are located today. At this very point, water escaped from cracks in the bedrock. Calcium that had dissolved from the volcanic rock was washed away. In the process, the calcium reacted with sulphur that had either leached from the rock or was introduced by volcanic gases. One of the analysed gypsum deposits on the edge of Endeavour Crater is approximately 50 centimetres long and two centimetres wide. Prior to this discovery, Opportunity had not found anything similar to the gypsum deposit, which scientists refer to as the “Homestake.” According to Steve Squyres, principal investigator for Opportunity and professor at Cornell University in Ithaca, this mineral is common on Earth, but on Mars, this discovery is almost a miracle; the type of event that makes geologists jump out of their chairs. “This tells a slam-dunk story that water flowed through underground fractures in the rock,” says Squyres.
Eight years breaking new ground with maxon motors
In January 2012, Opportunity will celebrate its eighth birthday on the Red Planet. Originally, the mission was planned to last just 90 days. Since January 25, 2004, the rover has been exploring Mars on behalf of NASA. Opportunity has covered approximately 35 kilometres and, in the process, transmitted almost 162,400 images of the surface and the atmosphere of the Red Planet to the mission control centre in Pasadena, California.
Motors manufactured by maxon motor ensure that the Mars rover is able to safely navigate the surface of Mars. A total of 39 DC motors by maxon motor are at work in Opportunity, and they continue to diligently carry out their tasks. The precision drives are used to drive the robotic arm, the Rock Abrasion Tool (RAT), the camera operation, and the control mechanism for the six wheels that propel the 180 kilogram vehicle, 1.6 meters long and 1.5 meters high, across the surface of Mars.
The motors are largely standard products with diameters of 20 to 25 millimetres and an efficiency of over 90 percent. Minor modifications were necessary to adapt the motors for the harsh environmental conditions: the temperature on Mars can fluctuate from approx. -120 degrees Celsius to 25 degrees Celsius. In addition, the motors had to withstand the special conditions during the voyage to Mars. And the atmosphere, which largely consists of carbon dioxide, is also a very special environment for the high-precision motors. Originally, two rovers were active on Mars; however, since March 2010, NASA has been out of contact with Opportunity’s twin, “Spirit.” A next-generation rover is already on the way to resume where Spirit left off: “Curiosity,” a space lab launched by NASA in November, is scheduled to land on Mars in August 2012
With a robot orchestra no drummers, guitarists or panpipe players are required any more – all these instruments are played completely by robots. All features needed for the orchestra, from the mechanical components, to the electronics and the software, were developed by TeamDARE from the Netherlands. This team consists of a group of enthusiastic engineers that share a hobby in their free time: building robots. The project originated from an internship at the Eindhoven University of Technology in 2001. Ever since, TeamDare has been participating in various competitions, such as the “Eurobot” international robotic contest and the “Artemis Orchestra Competition”.
The objective of TeamDARE is to show, in a playful way, what is currently possible with robotics. With the music robots, the team proves that, to a certain extent, it is already possible to replace musicians with technology. The strength of the team lies in the balance and synergy between the different subject fields, from mechanical engineering and electronics to computer science. Thus a multi-disciplinary team has formed that closely cooperates to develop more music robots. The shared passion for technology is the largest motivation for the eight team members.
maxon motors for the right sound
Simplicity, robustness and the reliability of the individual components are important prerequisites for the implementation of the respective robot projects. However, the robots also frequently have to be transported to other locations for presentations. This demands great care, because any repairs that become necessary cost time that could otherwise be used for new projects. “Therefore we have been counting on motors by maxon for many years,” says Bart Janssen, the team leader.
The heart of the orchestra are the 17 maxon motors built into the three music robots. For example, the panpipe robot is equipped with three RE 25 maxon DC motors, with GP 32C planetary gearheads for driving the instrument. A total of eight motors are behind the beat of the complex drummer kit. This includes three maxon RE35 DC motors. The centerpiece of the DC motors is the worldwide patented ironless rotor.
“Using maxon’s motors gives us great creative freedom. Especially as the large variety offered by maxon includes the right solution for every function,” explains Janssen. In June 2010, the engineers completed the development of the panpipe robot. After a short break, the team is already hard at work on the next instrument. At the moment, TeamDARE will only reveal that the new music robot will not simply supplement the current “band members”—instead, it will surpass all the other instruments built until now in both scope and complexity. The suspense continues… Which musical robot will soon jam with the rest of the orchestra?
Imagine you enter a room and see a twin in front of you. It is not made of flesh and blood, but the humanoid robot already bears an uncanny resemblance to its human counterpart. In China, this scenario is no longer science fiction, it is reality. The lifelike artworks can blink, nod and move their arms and legs—thanks to drives made by maxon motor. A perfect interplay of technology and art.
The Chinese technology company Xi’an Chaoren Robots has mastered the art of combining a human appearance with the technical features of a robot, with fascinating attention to detail. The true-to-life exterior of the robot is modeled after humans. Even the hair on its head and its eyebrows are made of human hair and is painstakingly applied by hand. The elastic exterior of the android is made of silicone and feels almost like human skin. “With the lifelike appearance of the robot, we want to convey a human touch instead of portraying a cold machine as is the case with most other humanoid robots,” says Zou Ziting, General Manager of Xi’an Chaoren Robots.
And it really is almost uncanny when the robotic twin of Zou Ren Ti hardly differs from its real-life human counterpart. This robot is part of the first generation of lifelike robots. Seven years ago, the company based in Xi’an, the capital of the Shaanxi province in China, started to develop humanoid robots. The company has been marketing them since 2006. In the same year, Xi’an Chaoren Robots won the “Robot of the year” award of Time Magazine. Today numerous of the company’s androids are used at a wide range of events. For example, they can explain and present products to visitors of trade fairs and exhibitions. Today many museums, including the National Museum of China, are among the customers of the robot manufacturer. And even the Chinese TV station CCTV (China Central Television) has already ordered a robot double for nationally known TV presenter Li Yong. In the near future, the robots are to be equipped for tasks at home—for example as nanny, service robot or as nurses.
Each robot is unique
However, first the robot has to learn to walk, because currently its movements are still limited to basic functions. It can, for example, move its head in all directions. With its eyes, it can blink and look in different directions. Movements of the arms, wrists, legs and feet are also possible – for example, the robot is capable of waving to the public or tapping its foot. It also does not lack verbal skills. It’s mouth can move and talk by means of a remote control. Around six months is needed to complete a robot. Each robot is unique and has its own movement characteristics.
Blinking and waving thanks to maxon motors
Small, powerful motors are an important criterion for the life span of the robots. Zou Ziting explains that Xi’an Chaoren Robots chose motors manufactured by maxon as drive technology, as they are small yet highly efficient. In total, 16 brushless motors from maxon motor are used for the third generation of robots made by Xi’an Chaoren Robots. For example, the robot twin of the Chinese TV-presenter Li Yong is equipped exclusively with motors by maxon.
The precision motors have a diameter of 16 to 40 mm. One of the motors used is the EC-i40 flat motor combined with the GP 32 C planetary gearhead. This drive combination is responsible for the movement of the robot arms. For the planetary gearhead, the company chose the version with ceramic axes, as much higher torques can be achieved than is the case with steel axes and the wear-resistance of the ceramic axes are much higher than that of steel axes. Like the android called Hubo, manufactured by the Korea
Advanced Institute of Science and Technology, the humanoid robots from China are equipped with the energy-efficient, dynamic maxon EC-4pole drive. Thanks to a rotor with two pole pairs, this drive can achieve a very high power density. With the powerful 120 W of the EC-4pole 22, the robot can take a bow on command. Motors manufactured by maxon also control the movements of the eyes, eyelids and mouth.
In the near future, the “human” robots will get even more intelligent with the aid of maxon’s motors. In addition to human facial expressions, the robots will soon take their first steps and react to spoken commands.