Zizzy: A Personal Robot Assistant

Zizzy is a personal robot prototype for people with limited mobility. It can talk, show emotions, and manipulate desktop objects.

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Zizzy is a personal robot prototype for people with limited mobility. It is designed to move freely on a smooth desktop or table. It can talk, show emotions, and manipulate food, water and communication devices. It can also do pill sorting and provide medication. It can move autonomously in pre-programmed sequences or be remote controlled by the user. At 12.5 inches high, it does not take up much space.

The head, body, arms, mounting brackets, air control valves, and the artificial muscles that actuate the two arms and grippers, are all 3D printed.

This robot is all open source hardware and open source software. Anyone can take what I have done and use it freely, and hopefully, improve on it.

While quite functional, this is just the start of the most advanced robot I have so far built . It is not yet the finished and ultimately useful robot it can be.

The two arms can be used to pick up objects and move them to the person controlling it. It can be used to provide medicine, food and water or manipulate a phone, tablet, or other device. The voice circuit can be used to facilitate communication for those with limited or no speech. The face is basically an emoticon that can be used to display emotions.

Zizzy the robot, can be remote controlled using infrared signals from a standard universal remote control. An infrared remote control could easily be modified to interface with a wheel chair, puff and blow, or other type of controller. This would allow the operator to remote control all motions or to activate pre-programmed sequences.

Project detail picture shows the new arms and grippers installed.

Modular Construction

This robot uses modular construction with the muscles and grippers able to plug in and out to allow for easy replacement or upgrades whenever a better design becomes available. The talking circuit and master robot neuron also plug in and out to allow for upgrades.

The Future Of Robotics

I believe the future of practical and affordable robot assistants will involve soft artificial muscles such as those used here. They are lighter and less expensive than the standard gear motors and power servos used by most present day robots. They are also less dangerous around humans as they have a certain amount of built in give if they push against a human. While some gear motors and servos will still be necessary, many can ultimately be replaced with air powered artificial muscles. While there are many experimental artificial muscles in the works, air powered artificial muscles are the only practical muscles available today for small robots.

While much is made about the purely soft robots that have little or no bone structure, my previous soft robot experiments have shown that a fairly stiff skeleton with hinge joints is neccessary with soft robot artificial muscles to get precise movements that are easily repeatable.

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  • Making Zizzy Tetherless

    Michael Roybal10/02/2016 at 18:53 0 comments

    Two small 12 volt air pumps are now hooked in series and mounted in a backpack, to get 24 PSI of pressure. This eliminates the hose tether to the offboard pump. It is working fine but is still somewhat noisy. Work has begun on making a quieter pump that would work by compressing an artificial muscle with a gear motor cam.

  • Testing The New Arms And Grippers

    Michael Roybal10/02/2016 at 18:48 0 comments

    The two new arms and grippers have been installed and tested. They are much stronger and can now carry a water bottle or can of beverage. They can also manipulate small items like a stylus or medical pill.

  • Improving The Artificial Muscles And Arm Exoskeleton

    Michael Roybal08/21/2016 at 18:37 0 comments

    I have just finished designing and testing new 3d printed artificial muscles to replace the previous ones. They occupy a slightly larger volume and are considerably stronger than the previous versions. In addition, the plugs that held them in place have been removed and they now slot into a shelf in a redesigned exoskeleton.

    The new arm exoskeleton with the new artificial muscles now can rotate about 82 degrees which is an improvement over the 47 degrees of the previous arm configuration. For some reason, after many tries, I have not found a way to get a full 90 degrees of rotation with the muscles and hinge joints currently used.

    I will post the STL files for the new muscles and arm exoskeleton as soon as the new arms have been fully installed.

  • Parts That Are Being Improved

    Michael Roybal07/21/2016 at 16:05 0 comments

    To finish this robot and make it fully functional, here are some more things that need further development:

    Finish Face And Voice Phrases
    The face is not yet fully functional and new words and phrases need to be added to the vocabulary.

    Full Remote Control
    At this point, only minimal remote commands have been programmed. A new high speed valve will be added to increase precision.

    New Arm Joints

    A new arm exoskeleton is being designed that allows for 80 degree movement of each joint. The current hinge joints and muscles only allow for 48 degrees of motion.

    Improved Gripper
    I have designed a slightly larger and much stronger muscle that will be integrated with a new and stronger gripper design.

    Add Sensors
    At some point, I am hoping to add infrared sensors to a scanner on the head that will locate a human face to orient the robot.

  • Improving The Robot

    Michael Roybal07/21/2016 at 15:45 0 comments

    Noise Problems
    As the video reveals, the air pump is fairly loud. I am trying to find small battery operated compressors that are less noisy. If anyone knows of a good source for small and quiet air pumps, please let me know.

    Power Problems
    Since testing the robot I have designed some new, slightly wider muscles that are considerable stronger. Small changes in the geometry of the artificial muscles can significantly effect the power output. I may redo the arm exoskeletons to incorporate the new muscles.

    Removing The Tether
    For now, the artificial muscles are powered by a 1/8 inch hose tethered to an off board air pump. To make it tether-less, I am working on adding a backpack containing two small battery operated air pumps. They will to be hooked in series and mounted in a sound deadening enclosure on the back of the robot.

  • Testing The Robot

    Michael Roybal07/21/2016 at 15:37 0 comments

    The robot as tested so far is fairly strong and quite reliable. The 3D printed valves are fully functional but the muscles and arm joints could be improved upon.

    The video shows the robot in a pre-programmed sequence--picking up a water tube and power bar and taking it to the edge of the table. From there it could be remote controlled to feed the operator.

  • Building The First Prototype

    Michael Roybal07/21/2016 at 15:20 0 comments

    It took over a year to make the first working prototype of the personal robot. During that time, I 3D printed and experimented with over 240 designs for artificial muscles. The most powerful muscles with the minimum volume were eventually used to power the arms and gripper. Pic shows a few of the designs that were tried.

    3D Printing Valves
    Solenoid air valves are quite expensive and heavy. They also take up too much volume to fit in a small robot. So I also experimented with 3d printing servo controlled valves using micro-servos. One servo can control 3 valves.

    You can download ready to print STLs and see details on making the valves here:

    3D printing the arms and body
    The robot arm is printed in one piece using PLA. It contains four built-in hinge joints. The air powered artificial muscles are printed in Ninjaflex and after they are sealed, they simply pop into the sockets built into the arms. One bolt holds a micro servo in place to rotate the wrist joint.

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Carlos A wrote 07/25/2016 at 22:26 point

I believe the air pump you need is a vane pump style. I was going to whip one up and test it out, but then found that they exist...

I may make one anyway because I need a small air ram for one part of my project. If there is any interest, let me know, i`ll document it. I am basing my knowledge on the internals of a vacuum pump and a diesel injection pump.

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