AWR1843BOOST: Verification of parameter information and Z-coordinate value analyze

Hi,

Can you please let us know what application you are investigating using the MRR demo for?

Thank you

Cesar

Hello Cesar

I am thinking of tracking rear vehicle application while ego vehicle is moving.

Thanks for your help. 

Hi,

Please note that, as described in the documentation, the mrr demo supports two types of frames

• TDMA MIMO (one TX enabled at a time)
• Beamforming (all 3 TX enabled at the same time)

Tracking is only enabled for the Beamforming frames.

If you are interested in tracking, you would need to enable Beamforming only mode as described in the documentation.

Please note that this mode is designed for mid range detection up to 120m. At this range there is no elevation (z) supported.

Elevation (z)  is supported only for MIMO frames

thank you

Cesar

Thanks for your response.

Please take me through my confusions below. 

1. Can you give me an example of how to calcuate / verify the parameters of MRR80h from the .c code (max range, range resolution or velocity resolution etc) ?

I am using my own tracking algorithm for the vehicle tracking, so I am interested in range, range rate, and angle from the sensor.

So I need to adjust the Radar parameters to optimize my tracking algorithm. (I do not use 'MRRVisualizer')

As far as I can only see, the parameters  of MRR120 and USRR30 are posted on the "MediumRangeRadar_DeveloperGuide.pdf"

Now I am using 'mrr_config_chirp_design_MRR80.h' so I want to know how to calcuate/verify the parameters that I mentioned above. 

Further I might need to adjust these on the .c code so it would be grateful if you guide me how to solve these.  

2. Analyze the Z-coordinate value?
I used both MRR and USRR frame when I took the data and I set up this sensor at around 1 meter height of the vehicle. But I can see the Z-coordinate values are less than -1 meter (I can see -5 or -6m often). How can I understand these values?

Hi,

Let's first address the first question.

In order to understand the chirp/frame configuration, you will need to refer to the following documents:

1) This document provides the equations that define the max range, range resolution or velocity resolution etc..

https://www.ti.com/lit/an/swra553a/swra553a.pdf

2) In order to understand how these equations are derived you should review this training: Intro to mmWave Sensing

https://www.ti.com/video/series/mmwave-training-series.html

3) In order to understand the units of the configuration parameters, you need to use the Radar Interface Control Document provided in the Device Firmware Package Release:

C:\ti\mmwave_dfp_01_02_06_03\docs\mmWave-Radar-Interface-Control.pdf

AWR_PROFILE_CONF_SET_SB, section 5.5.1 provides the profile configuration

AWR_CHIRP_CONF_SET_SB provides the chirp configuration

AWR_FRAME_CONF_SET_SB provides the chirp configuration

With this information you should be able to make sense of the attached document that shows how to compute the parameters of interest

The computation in the document is for MRR120.h configuration but you should be able to compute for the MRR80.h

Thank you

CesarMRR_Configuration.docx

Thanks for your kind response!

1. Based on the calculation with using parameters of MRR120h, Maximum range could be 174m but why do we consider the maximum range as 150m?

2. Also, I calculated the range resolution based on the formula (Range resolution = c/2*B), I can see the result as 62.5cm but the manual says range resolution is 68.2cm. Why are the values are slightly different?

3. Based on the calculation of Vmax, why did you use total chirp time times 2? (Vmax=3*10^8/((76*10^9)*(4*53*10^(-6)*2))=9.3098m/s=33.515km/h). And How did you get the total chirp time? Should it be idle time + ADC start time + ramp end time, which is 5us + 3us + 44us = 52us. However, your calculation used total chirp time as 53us. Please take me through the difference. 

#define PROFILE_USRR_IDLE_TIME_VAL (500U)
#define PROFILE_USRR_RAMP_END_TIME_VAL (4400U)
#define PROFILE_USRR_TX_START_TIME_VAL (100U) // 1us
#define PROFILE_USRR_ADC_START_TIME_VAL (300U) // 4.8 us < The annotation probably could be 3us.

4. For deriving velocity resolution, how can I get the 'number of chirp in a frame(N_c)' on the code? Based on the manual, the number of chirp for USRR is 128 though. 

Hi Cesar

Thanks for your detailed reply. 

You mentioned: With the antenna of the AWR1843BOOST EVM we will not be able to detect at the maximum range

Does this mean that theoretical range could be considered as 150m (based on the manual), or 174m (based on our calculation) but the radar actually can measure more than / less than the theoretical range given the environment condition?

And I mentioned about z-coordinate values which spit out -5~-6m even though I set the sensor up on the 1m height. 

Can you also elaborate why these values are measured or how can I understand these value?

Thanks for your help.

Hi,

Sorry for the delay.

The antenna will allow to measure only ~120m for a moving car at the most. You can perform some experiments as well.

Observing z = -5, 6 m is not correct

Do you have a corner reflector to test?

Thank you

Cesar