Motorcycles

Students designing an omnidirectional sphere-wheeled electric motorcycle

Students designing an omnidire...
A group of students from the Charles W Davidson College Of Engineering at San Jose State University are working on an omnidirectional, self-balancing SDS electric motorcycle
A group of students from the Charles W Davidson College Of Engineering at San Jose State University are working on an omnidirectional, self-balancing SDS electric motorcycle
View 30 Images
An early test rig shows the three-motor drive system in operation
1/30
An early test rig shows the three-motor drive system in operation
The test rig is upscaled
2/30
The test rig is upscaled
The drive system is proved on a working test unit
3/30
The drive system is proved on a working test unit
The three-motor drive system can be seen clearly to the front of the test unit
4/30
The three-motor drive system can be seen clearly to the front of the test unit
Rendering of the SDS motorcycle with a transparent fairing
5/30
Rendering of the SDS motorcycle with a transparent fairing
The fairing gets a touch of color to mask many of the motorcycle's components
6/30
The fairing gets a touch of color to mask many of the motorcycle's components
Top view rendering of the SDS motorcycle
7/30
Top view rendering of the SDS motorcycle
Battery boxes ready for the Lithium Iron Magnesium Phosphate batteries with a built-in BMS
8/30
Battery boxes ready for the Lithium Iron Magnesium Phosphate batteries with a built-in BMS
The omniwheels prior to assembly
9/30
The omniwheels prior to assembly
Close up of the six omniwheels that give the vehicle its potential to move in any direction
10/30
Close up of the six omniwheels that give the vehicle its potential to move in any direction
Grip is added for traction
11/30
Grip is added for traction
Close up of the motor mounts
12/30
Close up of the motor mounts
Testing the Animatics Smart motor ahead of drive system assembly
13/30
Testing the Animatics Smart motor ahead of drive system assembly
All the electric drive system components ahead of assembly, including the omniwheels made from zinc-coated 4130 steel
14/30
All the electric drive system components ahead of assembly, including the omniwheels made from zinc-coated 4130 steel
Close up of the three-motor drive system
15/30
Close up of the three-motor drive system
Close up of the three-motor drive system
16/30
Close up of the three-motor drive system
Another view of the SDS motorcycle's three-motor drive system
17/30
Another view of the SDS motorcycle's three-motor drive system
The carbon fiber and fiberglass shells that form the front and rear spheres
18/30
The carbon fiber and fiberglass shells that form the front and rear spheres
The two halves of these shells were subsequently joined to form a sphere and then coated with a durable industrial rubber for traction
19/30
The two halves of these shells were subsequently joined to form a sphere and then coated with a durable industrial rubber for traction
The rather shiny frame is fashioned from 304 stainless tubing, and there's suspension front and rear in the shape of Fox racing shocks
20/30
The rather shiny frame is fashioned from 304 stainless tubing, and there's suspension front and rear in the shape of Fox racing shocks
Another view of the frame
21/30
Another view of the frame
The vehicle's spheres are contained within the swingarms
22/30
The vehicle's spheres are contained within the swingarms
The battery packs are installed and the SDS motorcycle is ready for the camera, but there's still a long way to go before it's operational
23/30
The battery packs are installed and the SDS motorcycle is ready for the camera, but there's still a long way to go before it's operational
The vehicle is about 85 percent assembled in terms of hardware and about 20 percent done in terms of software and electrical
24/30
The vehicle is about 85 percent assembled in terms of hardware and about 20 percent done in terms of software and electrical
A group of students from the Charles W Davidson College Of Engineering at San Jose State University are working on an omnidirectional, self-balancing SDS electric motorcycle
25/30
A group of students from the Charles W Davidson College Of Engineering at San Jose State University are working on an omnidirectional, self-balancing SDS electric motorcycle
Final rendering of the SDS electric motorcycle
26/30
Final rendering of the SDS electric motorcycle
The initial aim is to get the vehicle stable and in control at speeds up to about 10 mph but the designers say that, in theory at least, it could zoom up to 60 mph
27/30
The initial aim is to get the vehicle stable and in control at speeds up to about 10 mph but the designers say that, in theory at least, it could zoom up to 60 mph
The SDS electric motorcycle that rides on spheres instead of wheels and features self-balancing technology
28/30
The SDS electric motorcycle that rides on spheres instead of wheels and features self-balancing technology
The user will control the motorcycle just like any modern motorcycle with a throttle, leaning, and handlebars
29/30
The user will control the motorcycle just like any modern motorcycle with a throttle, leaning, and handlebars
There will also be a set of joysticks that will allow for additional maneuvers such as forward/reverse/side-to-side motions/spinning the vehicle
30/30
There will also be a set of joysticks that will allow for additional maneuvers such as forward/reverse/side-to-side motions/spinning the vehicle
View gallery - 30 images

Thanks to gyros, accelerometers and sophisticated control mechanisms, remaining upright on a two-wheeled vehicle is no longer quite the balancing act it might once have been, even when at a standstill. Visions of future mobility like Honda's U3-X take such ideas in whole new directions, quite literally, by including multi-directional capabilities, and concepts such as Supple go even further still by ditching wheels altogether in favor of balls. It's this freedom of movement that inspired a group of students from the Charles W Davidson College Of Engineering at San Jose State University to begin work on the ambitious Spherical Drive System (SDS) electric motorcycle.

The SDS concept vehicle is described as a self-balancing electric motorcycle that rides on spheres. Rather than using the kind of mechanical gyros that help keep the Gyrobike or the C-1 from Lit Motors in an upright position, the SDS creation uses data from MEMS gyroscopic sensor technology and an onboard accelerometer to electronically control balance.

There will also be a set of joysticks that will allow for additional maneuvers such as forward/reverse/side-to-side motions/spinning the vehicle
There will also be a set of joysticks that will allow for additional maneuvers such as forward/reverse/side-to-side motions/spinning the vehicle

A Robot That Balances on a Ball

"The motorcycle operates on a friction based drive system that directly drives the surface of the sphere with custom manufactured omniwheels, attached to Animatics motors," explained team leader Max Ratner. "The method for balancing the motorcycle is similar to a Segway in that it uses accelerometers and gyros for detecting the pitch angle and correcting for any displacement from vertical. The user will control the motorcycle just like any modern motorcycle with a throttle, leaning, and handlebars. Additionally, there will be a set of joysticks that will allow for additional maneuvers such as forward/reverse/side-to-side motions/spinning the vehicle."

The electric bike's three-motor drive system that gives the vehicle its potential to move in any direction is modeled after a system known as an inverted pendulum, and features omniwheels made from zinc-coated 4130 steel and Animatics Smart motors powered by Lithium Iron Magnesium Phosphate batteries with a built-in battery management system. The rather shiny frame is fashioned from 304 stainless tubing, and there's suspension front and rear in the shape of Fox racing shocks.

The vehicle's spheres are contained within the swingarms
The vehicle's spheres are contained within the swingarms

The vehicle's computer-controlled operation (much of which is undertaken using an ARM architecture microcontroller) should help keep bike and rider safe, but if the vehicle were to leave the ground for any reason, the spheres will remain contained within the swingarms. Ratner told us that the "spheres are essentially carbon fiber and fiberglass shells, coated with a durable industrial rubber for traction."

The SDS motorcycle is still very much a work in progress and, now that original team members have graduated, only Ratner, Henry Li and Andrew Parmar remain on the project full time. The initial aim is to get the vehicle stable and in control at speeds up to about 10 mph (16 km/h) but the designers say that, in theory at least, it could zoom up to 60 mph (96.5 km/h).

There is still quite a bit to do before then, however. Ratner confirmed that "the vehicle is about 85 percent assembled in terms of hardware and about 20 percent done in terms of software and electrical. We have about 90 percent of our parts."

Work on the control system is currently being undertaken by three new recruits from San Jose State University (Lynn Comiskey, Evan Ly and Jessica Chen) as part of their own class project.

"The challenges posed by the control system include an attempt to balance an inherently unstable system, interfacing with multiple drive motors, and combining potentially noisy sensor readings such as those from an accelerometer into something usable and reliable," Ratner told us. "The control system has been proved out on our test rigs but there is quite a bit of stuff to change in the code to make it applicable to the final bike. This testing will likely happen around the end of 2012."

The vehicle is about 85 percent assembled in terms of hardware and about 20 percent done in terms of software and electrical
The vehicle is about 85 percent assembled in terms of hardware and about 20 percent done in terms of software and electrical

Backing from companies and organizations like Animatics, Wolfe Engineering, Atmel and IEEE has helped toward meeting project costs, and the team is presently on the lookout for sponsors to help mold and manufacture the fairings that will hide much of the exposed workings and help enhance the vehicle's already striking appearance.

Source: SDS (and you can follow project progress via the SDS Facebook page) via The Kneeslider

View gallery - 30 images
28 comments
Two Replies
Looks like something that should have been in iRobot.
sk8dad
Why even have two balls? Why not just a single ball...er...like a unicycle? What happens when the ball sucks up a piece of road debris and jams inside the drive mechanism?
Udhaya Kumar
Why don't we apply electro osmotic pressure like earth worms do to the spherical wheels
MasterG
What happens when it gets wet? Its friction based and slippery balls are not desirable for friction driven systems. How will you take a bend? In essence one of the joys of biking is the lean to turn. on balls that are trying to keep you upright you will then transfer the inertia to your head as you try taking a nice fast bend while sitting upright. To make this thing anything better than a curiosity would mean absolute control of driving the ball without using a frictive system.
Pikeman
Heavy, expensive, and no traction in the rain. If i was the professor I would have tried to keep it from ever seeing the light of day even if I did give the students good grades.
Forward Thinker
I bet those ball-tires would be useful in warehouses where there's not always a clear path to move around. Put a couple on a platform and use it to carry loads around piles of stuff in storage. I've worked in a warehouse before and something like that would have been a whole lot easier to work with than a standard pallet jack.
Gregg Velosi
Absolutely awesome. It could do nothing but putt around in the lab & it would still be cool!
Think of this little mod...turn that whole passager carriage 90 degrees, drop it a few inches & roll between the spheres instead of parallel. Make it so!
Very appealing design, hats off to ya
Denis Klanac
Forward Thinker, my thoughts exactly. this would be great for use on a forklift.
Nitrozzy7
Quote: "Heavy, expensive, and no traction in the rain. If i was the professor I would have tried to keep it from ever seeing the light of day even if I did give the students good grades." -Pikeman
Reduction in weight is eminent. This is a prototype designed to demonstrate the concept and tech. Pricing depends on many things. Most times the result is a far LESS expensive solution than the prototype. If they want to market it as a product, they will make it a fair deal. Traction in the rain may seem like a design fault, but you're forgetting that this design isn't a real-world design. Its sole purpose is to demonstrate the concept/tech. Motors that are capable of spinning at a much higher rpm, can and will offer a better basis for real-world applications.
And simply because you think something is not going to work, doesn't give you the right to cap people's ideas. I can think hundreds of implementations for the current model and you're lacking the capacity to think of one. Heck, you even have the audacity to say "If i was the professor I would have tried to keep it from ever seeing the light of day even if I did give the students good grades", the very moment where this design got such a good response. I can't help but wonder how many brilliant ideas where forever lost because of your inability to recognise them.
JPAR
impressive technology, even if the bike is flawed. One thought occurs to me - could this be developed into an ultra mobile wheelchair using a single ball device?