• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 31 subscribers
  • Views 4848 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

IWR1443BOOST + X-Y-Z coordinates + Arduino Uno

Alexander Luis
Prodigy 180 points
Other Parts Discussed in Thread: IWR1443BOOST, IWR1443

Dear Community,

     As a retired physics and mathematics teacher with the Boston Public Schools, I have been very interested in constructing projects in the area of physics education. I am not an engineer or computer programmer (learning C++), but I have been teaching myself how to code for the Arduino platform and in Processing (the graphing software). The IWR1443BOOST Evaluation Module (mmWave sensor) is of great interest to me, but can’t tell if the hardware would apply to my project.

As a background note, I have built several projects using the Arduino Uno and the PixyCam Camera (CMUCam5) to capture x-y-z coordinates, but unfortunately the Pixy’s frame rate is 50 fps.

Background on project:

I want to collide two 4.5,mm, or two 6 mm BB’s pellets (plastic, copper or steel and even two Ping Pong balls) and obtain their x-y-z coordinates for one second at 1000 fps if possible, and insert the data into an Arduino Uno Array to be scattered plotted in Processing (software). The event will be triggered by the BB pellet passing through a velocity chronometer (presently connected to Arduino Uno on Macintosh). Again, I’m not an engineer, but kindly request information or guidance of the feasibility in using the IWR1443BOOST for my measurements. 

Questions.

1. Will the IWR1443BOOST detect the x-y-z coordinates and velocity for the pellets mentioned above? The collision will take place inside a one-meter cube chamber.

2. Is any information available (code , schematics) for working with the Arduino Uno platform?.

I want to thank the forum very much for their time an effort in steering me in the right direction and for any resources that will educate me.

Sincerely,

Alexander Luis

  • 0
    TI__Mastermind 30405 points

    Hi Alexander,

    Thanks for the interest in TI mmWave Sensors. These sensors are based on Frequency Modulated Continuous Wave (FMCW) radar technology and provide the capability to natively sense range, velocity and angle of arrival (using MIMO techniques) of the objects in front of the sensor. The detectability of a target depends upon various things, such as distance from the sensor i.e. range, range resolution, velocity, and  the ability of the target to reflect radar waves which is quantified as the RCS (Radar Cross Section) which is a measure of the target’s ability to reflect Radar Signals in the direction of the radar receiver.

    1. On your first question, the IWR1443BOOST EVM is capable of detecting x-y-z co-ordinates of objects in front of it and you can experiment with the IWR1443 mmWave Out of Box Demo and mMWave Demo Visualizer to evaluate the detection functionality. We have not experimented with objects that small but safe to say that they'll have a very low RCS (for context, the RCS of an average human is 1, Car is 5, Truck is 100 etc).

    Secondly, the minimum (or best) range resolution you can achieve with a 4GHz bandwidth is 4cm. In many applications it is important to be able to resolve two closely spaced objects as two separate objects, rather than detect them as one. The smallest distance between two objects that allows them to be detected as separate objects is referred to as range resolution. This primarily depends on the chirp sweep bandwidth that the radar sensor can provide. The larger the sweep bandwidth, the better the range resolution. TI’s radar devices support a 4 GHz sweep bandwidth that allows a range resolution of as low as approximately 4 cm. So with the best range resolution, you cannot separate objects if they are closer than 4cm.

    Also, I am not sure what max velocity do you expect to detect. You may find the following threads useful in order to understand if these sensors fit your velocity requirements:

    https://e2e.ti.com/support/sensor/mmwave_sensors/f/1023/t/611459

    2. With regards to question 2, We don't have any code/resources available for interfacing with the Arduino platform.

    I would suggest you to start by entering your use case parameters (maximum distance, velocity, velocity resolution etc) in the  mmWave Sensing Estimator  to get an idea of what is achievable with the IWR1443 w.r.t.your requirements.

    Additionally, the following link provides excellent educational resources (videos) on the basics of FMCW radar and mmWave technology in general and training videos on TI mmWave devices. 

    https://training.ti.com/mmwave-training-series

    Whitepaper on mmWave: http://www.ti.com/lit/wp/spyy005/spyy005.pdf

    Regards

    -Nitin

  • 0 in reply to Nitin Sakhuja
    Prodigy 180 points

    Dear Nitin,

    Thank you very much for responding and education me on this very promising sensor.

    With my limited engineering background I hesitate asking questions being aware most members of this forum are engineers and programmers, Still, I’m so intent on making this project work that I purchased an Asus PC (I work on a Macintosh).

    You mentioned that the ” minimum (or best) range resolution you can achieve with a 4GHz bandwidth is 4cm.”

    Question: 1.

    Where does the “sub millimeter resolution come in? Since this sensor can detect at the micron level, why can’t it detect my 4.5mm, 6 mm BB metal pellets?

    Question2.

    Can I change the GHz sweep in order to detect my BB’s ?

    The velocity of my BB’;s are between 50 feet/sec and 100 feet /sec, thus obtaining the Tc values of 32.8 micro-sec and 65.6 micro-sec respectively.

    Question 3.

    Are the above times slow enough to capture my BB’s at thoses velocities?

    I am presently reading and studying the properties of this sensor, and will work with the Texas Instruments hardware and not the Arduino until I start getting some results.

    To start I’’ purchase the IWR1443BOOST and the SimpleLink MSP432P401/R and will down load the mmWave Software Development Kit (SDK), The Sensing Estimator and the Power Optimized Level Sensing Software to start.

    Question 4.

    Am I missing anything else?

    Again, thank you very much for your patience and support.

     

    Sincerely,

     

    Alexander Luis

  • 0 in reply to Alexander Luis
    TI__Mastermind 30405 points

    Please find my responses below:

    Question: 1.

    Where does the “sub millimeter resolution come in? Since this sensor can detect at the micron level, why can’t it detect my 4.5mm, 6 mm
    BB metal pellets?

    TI mmWave radar devices (and mmWave technology itself) can enable sub-millimeter level "Accuracy", not "Resolution". Let me try to  elaborate: In conventional measurements, Accuracy cannot be better than the resolution simply because Resolution is the finest your scale can measure. However, in Radar terminology, Resolution (Range Resolution) is always referred to in context of two (or more) objects and is defined as the smallest distance between two objects that allows them to be detected as separate objects. This is a physical limit (Range Res = c/2*B, where c is the speed of light and B is the sweep bandwidth) and depends on the chirp sweep bandwidth that the radar sensor can provide. The larger the sweep bandwidth, the better the range resolution.

    So fundamentally, with a maximum bandwidth = 4GHz, the range resolution is about 4cm.

    Now, Range accuracy which depends upon Range resolution can be better than range resolution:

    Range Accuracy

    This is often defined as a rule of thumb formula for the variance of the range estimation of a single point target as a function of the SNR. Essentially, this is a measure of how well we can determine the true range of the target. Range accuracy is a function of Range Resolution and SNR.

    *Note: This is the theoretical maximum accuracy and additional post processing may be needed in software to achieve this value. The theoretical max range accuracy is a function of Range resolution and SNR. It is defined as Range Accuracy = Range Resolution / Sqrt (2 x SNR). However, the achievable accuracy also depends upon (limited by) the size of the FFT as it defines the FFT resolution (aka range inter-bin resolution). Intuitively, the FFT granularity needs to be fine enough to measure the desired range increment and so the application may need to first get an initial coarse range measurement using the provided chirp configuration and then perform a zoom FFT on the range of interest, using additional processing in software with a higher order FFT.

    Please refer to the following threads on considerations related to high precision measurements. One main point to note is that to achieve sub-millimeter accuracy, the object needs to be stationary for a a few seconds.

    https://e2e.ti.com/support/sensor/mmwave_sensors/f/1023/t/597434

    https://e2e.ti.com/support/sensor/mmwave_sensors/f/1023/t/612730

    It may be possible to detect your BB pallets but we haven't experimented with objects that small. You can start by first trying to detect stationary pallets with the 1443 OOB Demo using the mmWave Demo Visualizer.

    Question2.

    Can I change the GHz sweep in order to detect my BB’s ?


    The velocity of my BB’;s are between 50 feet/sec and 100 feet /sec, thus obtaining the Tc values of 32.8 micro-sec and 65.6 micro-sec
    respectively.

    Absolutely, the devices allow you to program the Ramp Slope and Bandwidth based on your requirements. 100 Feet/sec is 109 KM/hr which is well within the maximum velocity. The devices are capable of natively detecting more than 250Km/hr. Please plug in your scene parameters (range, velocity, etc) in the mmWave Sensing Estimator to get an idea of the chirp parameters for your application.


    Question 3.

    Are the above times slow enough to capture my BB’s at thoses velocities?


    Already addressed in Question 2.

    I am presently reading and studying the properties of this sensor, and will work with the Texas Instruments hardware and not the
    Arduino until I start getting some results.

    To start I’’ purchase the IWR1443BOOST and the SimpleLink MSP432P401/R and will down load the mmWave Software Development Kit (SDK),
    The Sensing Estimator and the Power Optimized Level Sensing Software to start.

    I would recommend by starting with trying to detect stationary pallets using the mmWave Out of Box Demo rather than the Level Sensing Design as it is easier to start with and gives a continuous graphical view of the Range, Velocity (and 3D view) etc.


    Regards
    -Nitin

  • 0 in reply to Nitin Sakhuja
    Prodigy 180 points
    Thank you very much Nitin for your suggestions and explanation. I just ordered the IWR1443BOOST along with the MSP-EXP432P401R .
    Sincerely,
    Alexander Luis