Pistonrobot details area as of 9-26-2015
We have the legs pretty much complete. We have inserted some 2D graphic images to show how they look. There is a right and left leg. You may feel the left leg is just a copy of the right, except actually the legs do not have longitudinal symmetry and just a copy would not work. Instead, the left leg is a mirror image of the right, and vice versa.
Our latest job was attempting to illustrate internal and external rotation of the hips.
We discovered that just pure internal and external hip rotation, (that is to say, the hip movement is limited to only rotation about the long axes of the hips) creates a problem. This problem is that hip rotation limited in this manner creates a posture that even though the motion is physically possible both for the robot and for people, it is a motion that forces the legs to not look natural or correct.
If one watches people perform internal and external rotation of their hips in an unprompted natural manner, they will add abduction and extension of their hips to the rotation. What is intriguing is that, for each leg, if you take the point of the pelvis that is bearing weight, and move vertically straight down from this point, then with just pure internal and external rotation of the hip, the point where the weight of the pelvis points down to is moved from its normal location of just anterior to and just medial to the heel. The abduction and extension of the hip that is naturally added to hip rotation moves this point of weight bearing back to the location where it tends to be when a person is just standing with the hips in their neutral position. Also, these additional motions of the hips will geometrically alter the relation of the feet with respect to the ground. Again, what we discovered with people just doing natural motions of the hip, is that, once they add hip abduction and hip extension, they will, in order to keep their feet level with respect to the ground, also add eversion and dorsi-flexion of the foot.
These 2D views of the pistorobot legs are derived from the SketchUP drawing file listed below. If one really wants to get a true appreciation of what is going on with the legs, then the best approach is to download this SketchUP drawing file and open it with the SketchUP program. (Remember, there is a free downloadable version of the SketchUP program).
So here’s the views, there is a view that is the pdf export and a view that is the png export. The png’s are much prettier, but they are also larger.
We suggest download the png’s and open them with the Microsoft media viewer and enlarge them, then look around. There’s a lot of cool stuff to see. Enjoy
First view: (as a png file) (note for all the views below: each view has 2 different views of the legs as the hips are rotated. Upper set of leg views: showing various amounts of internal and external hip rotation where this rotation also includes, hip abduction, hip extension, foot eversion, and foot dorsi-flexion. Lower set of leg views: showing hip rotation only
same view as a pdf: Pelvis right and left leg with and without hip abduc and ext copy of v698.pdf
Second View: (png file)
same view as a pdf: Pelvis right and left leg with and without hip abduc and ext copy of v698 2nd view.pdf
Third view: (png) Third view as a pdf: Pelvis right and left leg with and without hip abduc and ext copy of v698 3rd view.pdf
Fourth view: (png) Fourth view as a pdf: Pelvis right and left leg with and without hip abduc and ext copy 4th view of v698.pdf
We also want to mention that we have begun some of the discussion of how we suggest to measure the extent of extension and retraction of the pistons that serve as the source of motive power to get the parts of the pistonrobot to move. It is our feeling that this is the key feature of pistonrobot that makes a piston based robot possible. We’ll have more detail on it in following posts, but we wanted to show the poster session that we put together in SketchUP. As we have done before, we will list the SketchUP skp file first and then a 2D export of that file so you can see it here at the website.
Here’s the skp file: Piston BasedTransceiver with text v85.skp
This jpg helps to show our plan to use integrated circuit components to create a capability for a computer to continuously, easily, and reliably acquire a digitalized data stream indicating with high precision the exact position of a piston head inside of a cylinder. This capability is essential to our plan to create a Pistonrobot that will be successful. More detailed discussions of this topic and a set of videos are all planned. A few more jpg’s are also listed on our page named Pistonrobot Sensory System.
And here’s the jpg export:
The piston robot site will use models initially drawn via the program named SketchUp. The SketchUP series of programs are owned by Trimble, and the Trimble web site is www.trimble.com. Among the versions of SketchUP, there is a commercial version named SketchUP Pro, and a free version named SketchUP Make, and these programs can be downloaded from the Trimble website. If you want to download any SketchUP models and work with them, you will need to install SketchUp on your computer. Trimble maintains a place on the web (named the 3D Warehouse) that contains collections of SketchUP models, including the actual model files which can be downloaded. PistonRobot sends some of its models to the 3D Warehouse, and you can find Piston Robot’s models by using the search term pistonrobot at the warehouse or by clicking here.
Above is the screenshot of the beginning video in our series of videos about using SketchUP to create the Pistonrobot. More videos are listed at the Videos page of the website. Our plan is that all of our videos will also be uploaded to YouTube, some are already there, more are coming. Above is a jpg export of one of our SketchUP drawings. The actual SketchUP drawing file is available for download at our model collection on the Trimble 3D Warehouse site, again our model collection on this site is named Pistonrobot.
So in conclusion
Welcome to all. We will describe on this site a bipedal walking robot and show the design and programming elements needed so that this walking robot could actually be constructed and can be made to walk. It’s gonna’ be fun, you just watch. The purpose of this site is to make it clear that such a robot could be built and that it will function just as it is described. We note that as of yet, the robot does not exist. Some of the important design features of the robot derive from the specifications listed above. We will have the robot to exist in a physical form that is very similar to the human. Since this robot will be a demonstrator that a robot can be created that exhibits the same type of balanced, graceful, fluid, and energy efficient motion as does a human, then we want to quickly stop the assertion that such a structure cannot be made and will not work. Shaping a robot so that it has a human form is ideal to meet this requirement for fundamental feasibility because one can contemplate the human form anytime one wants to, and one can see its form and motion. It makes no sense to look at the human in motion, and then assert that such a physical shape and form of motion is not possible. Of course it is possible, there it is right in front of you.