InvenSense gloats about world's first 6-axis MEMS-based motion sensing solution

We tell ya, some proud folks work at InvenSense. After boasting last year about its Wii MotionPlus-powering IDG-600 motion sensor, the company is set to gloat once more at E3 this year. The cause for celebration? Its 6-axis motion processing solution, which it's calling a world's first. Said solution weds its IME-3000 3-axis accelerometer with its IDG dual-axis family of gyros in order to produce a wicked small 6-axis motion sensor. In theory, at least, this creation is small enough to add MotionPlus-like capabilities to smartphones and other ridiculously small devices, with even TV remotes holding the promise of one day letting you "roll through" the EPG. Currently, the only big-name devices utilizing 5- or 6-axis motion functionality is Logitech's MX Air Mouse and the aforementioned MotionPlus accessory, but obviously InvenSense is hungry for more. Too bad that DSi already launched, right?

[why not the LS2LS7? @ May 28th 2009 2:12PM]

Didn't they gloat about this two weeks ago on here too?

Rotation sensing will always work better if you get further between the separate sensors. A small package like this may be easy to sell, but it won't work all that well.

[Tim @ May 28th 2009 2:41PM]

Actually the separation is only beneficial when you are attempting to determine rotations (angular rates) from accelerometers. In this case they have gyros to determine angular rates directly, and an accel determines the linear acceleration. The formulas to compute motion of a controller (assuming a rigid body) are much simpler when all your accelerations, and rotations are measured about (nearly) the same point.

[why not the LS2LS7? @ May 28th 2009 2:50PM]

Yes, I know it's only beneficial for rotations. That's why I said it in my message.

They may say this has a gyro, but there's really only two kinds of gyros they could use.

1. Laser gyros. That's not what it has, trust me.
2. Inertial gyros. Which is what it does have. But the problem is the inertial mass will be so small that the sensing will suck. Exactly how still does a MEMS jigsaw piece a few microns across remain when you rotate the device around it? Answer: not very.

You'll get better rotation sensing from moving the sensors farther apart, even though the math gets harder.

[pokey @ May 28th 2009 3:18PM]

It doesn't stay still. These work by putting a MEMS pendulum into oscillation and measuring changes in frequency. Usually the pendulum is a spring-loaded ring that moves slightly back and forth like a mechanical watch's balance wheel.

[Tim @ May 28th 2009 3:19PM]

Its actually a Vibrating Structure Gyro...totally different concept than a gimbaled inertial mass gyro as pokey mentioned.

http://en.wikipedia.org/wiki/Vibrating_structure_gyroscope

http://en.wikipedia.org/wiki/Coriolis_force

Regardless, I fail to see how moving a gyroscope around provides better accuracy in this care. Would making the vibrating proof mass larger help? Possibly. Spreading them out? Not a chance. It only applies to angular accelerations which is a terrible method to use since you have to integrate your signal twice, causing your bias and noise drift compound.

[why not the LS2LS7? @ May 28th 2009 4:39PM]

Very interesting. Hmm. It's gonna use more power than I would have hoped though, but I do see your point about it should be able to work in a smaller area than I suggested.

The reason to move sensors apart is to get more signal. If you are using XtYtZt sensors to measure rotation (as I assumed) this is critical, as you get correspondingly more signal the farther the sensors are from the center of rotation. But with this sensor I can see your point that moving them farther apart does not help and could easily hurt.

To answer my original question, they gloated about this 10 months ago on here.

http://www.engadget.com/2008/07/15/invensense-boasts-about-wii-motionplus-powering-idg-600-motion-s/

[tony @ May 28th 2009 2:51PM]

^ i get the point, mems is very fascinating

[SephirothsMoogle @ May 28th 2009 2:53PM]

So does the PS3's controller use 2 chips to achieve it's sixaxis?

[Mike Sylvester @ May 28th 2009 3:38PM]

Yes, an accelerometer and a gyro.

[Plothole @ May 28th 2009 7:26PM]

I believe it's one chip, but using a different, less accurate technology.

[superhobo @ May 28th 2009 3:13PM]

Do want.

[elBravo @ May 28th 2009 3:23PM]

Motion sensing remotes seems like a nightmare with IR. Everyone hated the PS3 bluetooth remote for it's lack of IR support. But I say its time for industry wide bluetooth support. Maybe this will be the push to bring it....

[Mike Sylvester @ May 28th 2009 3:45PM]

The PS3 BD remote doesn't have any motion sensors, but then it doesn't really need them for navigating the XMB. I use a Logitech MX Air for controlling my PC on my TV, and though it's not so hot for games (I actually tried playing UT3 on my PS3 with it, yeesh), it's just what the doctor ordered for PC on TV.

[MEAT! @ May 28th 2009 3:46PM]

Marketing can call it what they want, but this device does not detect motion in six axis. It detects motion along three axes: x, y, and z. -x, -y, and -z are just the negative components of those three axes, determined by an arbitrary intersection. That's all.

[LondonConsultant @ May 28th 2009 4:47PM]

You're missing the point. 3 axes are x, z and z positions (whether positive or negative). And the other 3 axes refer to the tilt direction, which is independent of the position.

[why not the LS2LS7? @ May 28th 2009 5:12PM]

They're talking about translational motion in 3 directions (Xt,Yt,Zt) and rotational motion in 3 directions (Xr,Yr,Zr). That's indeed 6 axes.

[MEAT! @ May 28th 2009 5:28PM]

What these sensors really provide are six degrees of freedom along three dimensional axes. Roll, pitch, and yaw can be seen as rotations around x, y, and z, followed by a translation.

[LondonConsultant @ May 29th 2009 5:46AM]

Meaty, You should just admit that you were wrong when, for some reason, you misunderstood 3 of the axis as being just negative translations. It's more dignified than trying to win a failing argument by waffling...

[MEAT! @ May 29th 2009 10:15AM]

I was definitely wrong that they name it six axis because of -x, -y, and -z. Still, I thought they were referring to dimensional axes, and "6dof" would be more accurate than "6-axis." This sensor detects accelerations along x, y, and z, and rotations along those same axes.

[Andrew @ May 28th 2009 4:05PM]

@why not the LS2LS7?
I just recently used MotionPlus, which this technology is being used in, and it works amazingly well. The slightest movement was picked up and represented on-screen. It's very impressive.

[Newone @ May 28th 2009 7:56PM]

It isn't world first single chip 6 axis sensor, at least Analog Devices have had one for ages. A bit higher package but still tiny.

[Plothole @ May 28th 2009 8:15PM]

They aren't claiming that it's the world's first single chip 6 axis sensor. But the first MEMS-based one.

[SmittyMcSmith @ May 29th 2009 8:31AM]

How is this the first 6DoF MEMS "IMU"? Analog Devices has 6 flavors of their 6DoF sensor with varying sensitivities and ranges as well as a 9DoF sensor, and a lesser 4DoF sensor all part of their ADIS series of devices.

•ADIS16300 - 4DoF (Tri-Axis Accelerometer with Yaw Rate Gyroscope) in a 31x23mm² package
•ADIS16350, ADIS16354, ADIS16355, ADIS16360, ADIS16364, ADIS16365 - 6DoF (Tri-Axis Gyroscope, Accelerometer, Magnetometer) in a 23x23x23mm³ package
•ADIS16405 - 9DoF (Tri-Axis Gyroscope, Accelerometer, Magnetometer) in a 23x23x23mm³ package

[Newone @ May 29th 2009 3:14AM]

Analog Devices one is MEMS-based.

"The ADIS16350/ADIS16355 iSensor™ is a complete triple axis gyroscope and triple axis accelerometer inertial sensing system. This sensor combines the Analog Devices, Inc., iMEMS® and mixed signal processing technology to produce a highly integrated solution that provides calibrated, digital inertial sensing. An SPI interface and simple output register structure allow for easy access to data and configuration controls."

[chris carter @ Jul 7th 2009 7:29PM]

came across this link on the invensense website... may prove to be helpful for answerin ur question regardin gyroscopes and gaming and the wii motion plus
http://invensense.com/applications/gaming/wii-motionplus/wii-motion-plus.html