Presented Master Thesis about EtherCat for machine control

Last July, the 10th, Ignacio Rosales finally presented his project based on the development of a machine control system using the real-time EtherCat protocol. This project has been co-directed by Víctor Torres López.

The machine is a pick-and-place machine which was previously developed as part of the 2012 Omron’s CEA award.

Extensive work for reverse engineering the Omron servomotors and integrating into the LinuxCNC fwamework has been required.

As a result, a new architecture for the development of machines, with an excellent real-time response and high flexibility has been tested.

In the video, a demo of the system can be seen.

Great work, Nacho!

 

Presented Master Thesis on autonomous electrical vehicles

The amazing work of Francisco García was bringing to life one of the old electrical tricycle used for people transportation inside the Expo’92 in Seville, last century.

His work was to design and implement an steering control system. We used new lead batteries (12 + 12V) and added a servomotor with direct coupling to the steering axe.

The controller has been implemented with an Arduno Mega and the PID control has been tuned and programmed in simulink.

For testing purposes, an open loop throttle control system has been added, making it easy to remote drive the vehicle using a PS2 wireless joypad.

It was bot hard and fun.

Thanks, Francisco!

3D printed vacuum ejector: First test

After a previous prototype which didn’t work, I tried to make a new one.

This time I decided to start from scratch with a new design and using ABS.
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I printed this part vertically to have better alignment in the main axis.

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Although some reinforcement with acetone was needed, the prototype is ready to hit the lab.

This time a quick and dirty trial using the hand air gun.

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The results are amazing!20150520_111807_HDR[1]Even without the silicon suction cups, this ejector was able to pick small and big parts.

See the video below

More about this is still to come.

 

Using Model-Based Development for Teaching Fault Tolerant Systems

I’m using Simulink’s Stateflow as a tool for teaching Faul-Tolerant Systems in the Master of Mechatronics at the University of Málaga.

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Using Stateflow for the developmet of Fault Tolerant Systems

One technique for the fault diagnose of systems is based on the modeling of the system as an Finite State Machine (fms), and all the possible trajectories as an special fsm called “diagnoser”. It is based on different methods and used in the classroom as published here.

In this case we are using this tool with surprisingly good results:

  • No programming needed (just modelling)
  • High level model is created with good implementation separation
  • The student starts building successful simple programs since the first moment
  • Teachers avoid the hassle of always changing IDE’s, versions, and implementation platforms.
  • Thanks to Harel diagrams, Complex systems with high readability can be modeled.
  • Teaching time is reduced.
  • Laboratory time is focused on the problem. Leaving spare time for proper documentation.

It’s not an open source platform, but definitely I’m going to use this tool extensively.

Thanks to my students.

Please, download and cite this work:

Gomez-de-Gabriel, J.M.; Mandow, A.; Fernandez-Lozano, J.; Garcia-Cerezo, A., “Mobile Robot Lab Project to Introduce Engineering Students to Fault Diagnosis in Mechatronic Systems,” Education, IEEE Transactions on , vol.PP, no.99, pp.1,1
doi: 10.1109/TE.2014.2358551
keywords: {Education;Fault tolerance;Mechatronics;Mobile robots;Navigation;Robot sensing systems;Engineering education;LEGO Mindstorms NXT;LabVIEW;fault detection and diagnosis;higher education;mechatronics;mobile robots;project-based learning},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsptp=&arnumber=6914629&isnumber=4358717

Presented Master Thesis about robot self-tooling

Today, Jose María Herrero presented his work about robot self-tooling.

Jose María Presented the Robot Self-tooling concept.

Jose María Presented the Robot Self-tooling concept.

This a new concept involving 3D printing and robotics, where a robot can build and change his fingers automatically.

This setup uses a 3D printer extruder and a fingerless gripper with two dynamixel ax12 servos. He also had to deal with VAL3 for the programming the staubli TX60, and made a program in Python to send the G-codes.

Check the video:

Good job, José María.

Building Zowi, the Open Source Robot

This was a very nice week-end project: building the BQ’s Zowi Open Source Robot.

You just need a 3D printer, 4 standard servos, an Arduino and cables.

Zowi Open Source Robot

Zowi Open Source Robot

I found the source at http://diwo.bq.com/zowi-cc-by-sa/

After the build I found some suggestions:

What a mess!

What a mess!

Hardware: Not all the servos come with the hub size used in the design.

Software: You have to manage to find the ocillator library and correct some misspellings.

Assembly:

  • The BQ arduino version is very cool but is not easy to find. You can use your standard arduino uno making a bigger hole on the head shell.
  • An extra hole for the switch is important too.
  • The hardest part is to fit the head shell with all the cables. A redesign with the arduino fixed toi the chasis instead of the shell could help

Many thanks to the BQ team!

 

New joints for the animatronic robot

Wall-e is an old animatronic robot we build for entertainment and social robotics research.

It is also used as a valuable platform for students projects.

Its joints are driven by different kinds of RC servos, and sometimes the servo axle is used as the robot joint. This is a weak design point and we had to change this.

We needed a neck replacement and we found a “Servo Block” kit for Hitec servos which was perfect for our robot. It was 29€ over our budget (0€) but the MechatronicMan foundation helped again.

Servo Block was perfect for our robot neck

Servo Block was perfect for our robot neck

 

As we ran out of budget we had to design and build new shoulders.

We originally used a Lynxmotion Servo joint with poor axial bearings but it was not solid enough.

Our new design used “standard” skates ball bearings. with two parts: A 3mm width aluminium plate and a 100mm width bearing support.

The old ISEL cpm 3020 did a nice work with a 3mm single flute straight carbide bit.

20140703_135424 (1)20140703_173840 After a sandblasting the plate looks very professional! isn’t it?

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And the final assembly with the quarter scale RC servo gives a solid joint for our robot.

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That’s all. I just wanted to show it.

In the future I’m not using RC servos anymore unless I build a toy robot.

By the way, the joint in action were seen in last post : Animatronic at the Postgraduate Courses presentation 2015-16

Bye.

Animatronic at the Postgraduate Courses presentation 2015-16

Our animatronic robot made a new appearance after some neck and shoulder surgery.

This was the first Postgraduate Course presentation of the University of Málaga.

We had to refurbish some of the Wall-e’s old joints, but he´s a good nice robot and did his job nicely.

Some work has to be done to improve the robot’s power system and battery charge. Anyone?

Many thanks again to my postgraduate students.

 

More videos of Wall-e in this playlist: