Developing Exoskeletons for children present their own engineering challenges simply because children are still growing.
Exoskeletons were largely developed for people that have sustained paralysis or suffer muscular dystrophy. For adults who have stopped growing there is no risk of outgrowing the exoskeleton. However for children their growth and ability present a multitude of challenges for design engineers. An exoskeleton that fits a six-year old perfectly may be much too small by the time the child turns seven. For a child with spinal muscular atrophy an exoskeleton is designed to recognise users are not completely paralysed but are able to move their legs to a certain extent. Sensors within the frame detect weak leg movements and respond immediately to provide support. As a result, the child is able control the exoskeleton directly with the legs.
Spanish company, Marsi Bionics, manufactures exoskeletons mainly for adults but have developed two exoskeletons for children, the Atlas 2020 and Atlas 2030. Weighing approximately 14 kgs it is made for children from 3 years up who have a neuromuscular disease. The exoskeleton can be adapted to various leg lengths and hip widths, so that it also fits teenagers up to about 14 years of age. The “Atlas 2030 is an upgrade of Atlas 2020”, explains Elena García, creator and co-founder of Marsi Bionics. “The main difference is that Atlas 2020 is intended for use in hospitals for gait training and rehabilitation, while Atlas 2030 is designed for use in private homes as an integral part of the patient’s everyday life. Both devices are ready for industrial production and until then, Atlas 2020 will continue to be used in hospitals for clinical research.”
maxon motor have five drive systems in each leg of the children’s exoskeleton. Brushless flat EC45 motors deliver very high torque in a compact design, coupled with inductive MILE encoders that act as sensors. The motors are controlled by servo controllers from maxon’s ESCON series. “EC flat motors provide the best power-to-weight and power-to-volume ratio”, explained Elena García. “This is a variable of paramount importance, as gait exoskeletons require high power but a very low weight and volume.” The exoskeletons will be made available commercially once CE certification marks have been received.
For more information contact maxon motor Australia Tel. +61 2 9457 7477.
Brushless flat DC motor with hollow bore for air and light transmission.
Today we exhibit a new motor development featuring a Brushless DC (BLDC) flat motor. Flat motors are also commonly referred to as pancake motors. This unit has a body length of just 38mm and an output power of over 157W and 6000rpm at the shaft in the application. The average motor power rating for the series across 6 variants is 100W. The overall motor diameter is 68mm and it can be supplied with or without protective covers for IP rating. The motor is available with an internal encoder with resolutions up to 16,384qc per revolution making it suitable as a rotary stage of robotic joint actuator. The unique feature though is the motors hollow shaft. This is to enable customers to pass light or air through the bore of the motor. Air transmission is a common requirement for packaging and placement machinery and light or fibre is a common requirement for film and camera gimbal applications. This motor was also manufactured with the customers shaft length and bore specifications in combination with a custom rear shaft extension at the rear from the motor rotor.
Contact maxon motor Australia for motor specifications or assistance with a custom solution Tel. +61 2 9457 7477.
maxon motor have released the 2018/19 catalogue. Entitled “High precision drives and systems” the new catalogue theme is based on maxon motors focus on building complete drive systems including DC motors, gearheads, sensors and controllers.
maxon motor will continue to be the world’s leading supplier of high precision brushed and brushless DC motors and gearheads but also have expanded into cross-platform system solutions from a single source. In addition to the new capabilities expansion maxon have released a large range of new products. These include: A new square format 16mm brushless DC motor, 13mm and 16mm ECX high speed brushless motors, the new ECi-30 low cost high torque BLDC motor, an entire range of frameless brushless motors that are particularly suitable for wheel hub applications and robotic joint actuation, new encoders and various new motor control units. The first torque levels from a direct drive maxon motor at 1Nm have been achieved with the new 260W flat motor that is less than 40mm long and a series of motors with a hollow bore are handy for applications that require a passage for cables, air or light. Print versions and online e-paper versions have been released.
For customised solutions contact maxon motor Australia Ph: +61 2 9457 7477.
For fine motor position control across multiple generation brushless motor controller models, maxon motor Australia has supplied the first of its kind maxon EC-max brushless DC motor with three modes of feedback.
The new micromotor encoder 16 Easy Absolute 16mm x 9mm offers high resolution motor feedback from a tiny package. Additionally it offers 4,096 counts per turn incremental outputs with line driver channels and an index pulse. The Absolute output is available in the choice of Binary BiSS-C or Gray Symmetric SSI. The encoders use an interpolated hall sensor angle measurement system to generate the incremental quadrature output signals according to EIA-422 with 20mA maximum current draw and ESD protections built in. The angle value zero of the encoder is factory aligned with the BLDC motor zero point and the encoder is welded in place on the rear flange of the motor. When fitted with a multi pole brushless DC motor the encoder can still show the angle values zero once per mechanical turn and the angle zero is identical to the index position. The motor itself also contains three hall sensors for commutation purposes. An adaptor is available to convert the single ended clock and data signals of the absolute encoder into TIA/EIA RS422 compliant differential clock and data lines.
For special configurations of this unique feedback solution with other maxon motor types contact maxon motor Australia Sydney office on +61 2 9457 7477.
maxon motor have developed their most powerful DC motor positioning controller to date.
With a maximum power output of 2.1kW maxon are pleased to announce the release of the EPOS4 70/15 DC motor positioning controller. The CANopen controller with an EtherCAT option is presented in a robust metal housing. Suitable for both brushless and brushed DC motors the positioning controller is a cut above the rest due to its ease of operation and broad operative scope. The various digital and analogue connections can be configured and the unit is suitable for use with a wide variety of feedback systems. It can also be integrated into various master systems. This new product and many more will be showcased at the Hannover Messe in Germany from 23-27 April. For more information please contact maxon motor Australia tel. +61 2 9457 7477.
There are additional connectivity options with maxon’s positioning controller, the EPOS4.
The addition of an expansion board now allows maxon positioning controller, the EPOS4, to be integrated into any EtherCAT network as a slave using the CoE standard (CAN application layer over EtherCAT). The EtherCAT card developed for this use can be combined with the EPOS4 controllers in a housing, as well as with all EPOS4 modules. The benefits widen the applications where compact positioning controllers are needed, for example where short cycle times are important in synchronized multi-axis systems.
EPOS4 controllers are suitable for controlling both brushed and brushless DC motors. They are known for their high power density and excellent value for money. For more information about maxon’s EPOS controllers, please visit epos.maxonmotor.com or tel. +61 2 9457 7477.
Brushless DC (BLDC) servomotor, zero backlash gearhead, holding brake and high resolution encoder combination drive offers high torque levels without compromising positioning accuracy.
This servo motor and gearhead combination recently released by maxon motor Australia can produce 364Nm with a peak torque rating at the output of 686Nm. Fitted with both an encoder and a holding brake inside the IP rated motor’s rear enclosure the combination can move heavy loads into position and make sure they stay there. The high acceleration of the brushless DC motor with top grade Neodymium magnets enables a zero to 2600rpm speed change in under 4ms. Being both brushless DC and also slotless gives the motor zero cogging or position detent for smooth position transitions and low speed performance. The solid construction and sealed nature of the motor drive components makes it suitable for mining, food, process control and manufacturing environments. Customisation of the motor and gearhead features is possible and both 24 and 48V DC supplies can be used. The unit is compatible with standard Servoamplifier and position controllers from maxon motor.
For more information contact maxon motor Australia Tel. +61 2 9457 7477.
An integrated DC motor, motor controller and sensor unit has been developed by maxon motor for use in sliding door systems.
Maxon have developed a compact drive unit for use in elevator doors, public transport, sliding doors or machine tools. Consisting of an EC90 flat brushless DC motor, with integrated mile encoder and an EPOS 2 position controller set within a single die cast carrier. Available in two options, both with 24V DC motor, the mdd1 offers 96mNm torque and 2000 rpm. The mdd2 has 730 rpm and up to 291 mNm torque. The modules can also be tailored to customer specific requirements.
For more information please contact maxon motor Australia on tel. +61 2 9457 7477.
This new combination of motor and gearhead can produce stable speeds over 120rpm with 10Nm applied.
With a very flat speed torque ratio the 40mm 170W brushless DC motor from maxon motor is suitable where minimal speed reduction is required under load. Particularly apt for process machinery or food production equipment where 24/7 continuous use regulated speed control is necessary. The pictured unit features a 2000qc incremental encoder and a 66:1 planetary gearhead. The output shaft is sealed and the unit can operate in small enclosures via conduction cooling. Brushless operation and ceramic components also give durability and robustness to the combination resulting in increased lifespan.
For more information please contact maxon motor Australia tel. +61 2 9457 7477.
When prototyping with Brushless DC motors information is key to product success.
Pictured here is a highly customised brushless DC motor developed for special aerospace applications. The 200W nominal 30mm diameter has had a special winding wound to suit the unique requirements of the application where the motor needs characteristics for driving and generation. It is a 4 pole topography with a sealed stainless steel body and welded flanges. The application for this brushless DC motor requires operation for very short bursts of power at over 500W. To facilitate testing that gives design engineers absolute confidence the winding will never exceed its thermal limits a platinum thin film temperature sensor has been fitted in contact with each phase. This allows the R&D staff to slowly increase the duty cycle whilst monitoring temperature and develop controller functionalities around the thermal limits. In addition the motor has been assembled with a planetary gearhead that is quite special in itself. The gearhead ratio has been slightly adjusted to allow for smaller planetary gear diameters. The smaller diameters allow for an additional set of gears on the output stage increasing the torque capabilities. A special 2RS rubber sealed bearing has been incorporated along with a customer specified axial threaded bore in the middle of the shaft. At the rear of the motor is a 4,096 quad count encoder facilitating the smooth zero cogging motion control.
Contact maxon motor Australia for a tailor made system solution Ph: +61 2 9457 7477.