AWR1642: How do I get vx vy by detObjFinal

user6419874

Part Number: AWR1642

Hi,

typedef struct MmwDemo_detectedObjForTx_t
{
int16_t speed; /*!< @brief Doppler index */
uint16_t peakVal; /*!< @brief Peak value */
int16_t x; /*!< @brief x - coordinate in meters. Q format provides the bitwidth. */
int16_t y; /*!< @brief y - coordinate in meters. Q format provides the bitwidth. */
} MmwDemo_detectedObjForTx;

According to MmwDemo_detectedObjForTx, I can know the speed is green line as bellow.

In SRR, I want to get vx, vy by detObjFinal.

Shall you support some sample code to reference?

Thanks

over 4 years ago

0 Ishita Kochar over 4 years ago

TI__Mastermind 31680 points

Hello User,

Our concerned expert will get back to you on this by tomorrow.

Regards,

Ishita

0 Aniket Mahajan over 4 years ago

TI__Genius 15046 points

Hi,

The MmwDemo_detectedObjForTx comes from pointcloud calculation. This just reports the radial velocity component of the object as the pointcloud processing cannot detect tangential velocity. (this is inherent for radar for a single observation)

The tracker can track objects across multiple frames to get an idea of the true velocity of the object, not just the radial component. The tracker output trackingReportForTx will contain the Vx and Vy velocity you are looking for.

Regards,

Aayush

0 user6419874 over 4 years ago in reply to Aniket Mahajan

Intellectual 385 points

Hi,

Thanks for your respond.

May I use the formula as bellow try to compute the Vx Vy?

Vspeed = ω * r

Vx = Vspeed * cos θ

Vy = Vspeed * sin θ

according to SRR code, I find

x = meas_rrd[iRANGE]*meas_rrd[iSIN_AZIM];

so I try to use

detObjFinal[ik].vx = detObj2D[ik].speed * detObj2D[ik].sinAzim;

but I find the value not correct.

Is something wrong as I know?

Thanks

+1 Aniket Mahajan over 4 years ago in reply to user6419874

TI__Genius 15046 points

Hi,

The velocity detObj2D.speed is only the radial velocity of the object (the green line in your diagram). Taking its component along x and y will not give the correct Vx and Vy velocity of the object.

As I said, you would need to use the tracker's output for this.

I went into the details of this same issue on this thread: https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/993307/awr1642boost-query-on-velocity-of-tracked-objects

Regards,

Aayush

Sensors

Sensors forum

AWR1642: How do I get vx vy by detObjFinal