PD420 FMCW Radar User Manual and Installation Guide K-Band FMCW Ranging Radar Built Types: PD420 Rev 1.4.2a DRAFT, September 11 2017 Open Frame PD420 Houston Radar LLC 12818 Century Drive, Stafford, TX 77477 Http://www.Houston-Radar.com Email: sales@Houston-Radar.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment.
Warning: PD420 radar is supplied in an open frame format with exposed antenna and electronics and thus is a static sensitive device. Please use static precautions when handling. Warranty does not cover damage caused by inadequate ESD procedures and practices. Note: Specifications may change without notice. Note: Not liable for typographical errors or omissions.
Table Of Contents INTRODUCTION............................................................................................................. 6 PRINCIPLE OF OPERATION ....................................................................................... 7 FMCW RADAR ................................................................................................................ 7 RADAR DETECTION ZONE ................................................................................................
Selecting an Operating Mode ................................................................................... 24 Selecting Clutter Time Constant and Performing Clutter Initialization................... 24 Defining Lanes .......................................................................................................... 24 Optimal Performance Checklist ................................................................................ 25 SYNCHRONIZING MULTIPLE RADARS ....................................
Introduction Congratulations on your purchase of the Houston Radar Ranging PD420 radar. This state of the art 24GHz K-band microwave frequency modulated continuous wave (FMCW) radar is specifically designed for the license free battery and solar operated presence detection market. Unlike regular Doppler radars, FMCW radars are capable of measuring range and detecting stationary targets.
Principle of Operation FMCW Radar PD420 FMCW radars modulate the frequency of the transmit signal in a linear fashion. The difference between the frequencies of the local oscillator and the signal returned from the target is proportional to the time delay between these signals and thus is proportional to the distance to target. In case of a moving target we also take into account Doppler shift of the return signal.
Also note that the radar beam is wider in one direction and the fundamental operation of the radar is not affected by the mounting orientation. This fact may be used to either widen or narrow the detection zone in the direction that matters. For a wider horizontal detection zone, mount the radar with the wider beam in the horizontal direction. For a narrower horizontal detection zone, mount the radar with the narrower beam in the horizontal direction.
Radar Pointing The radar beam may be pointed across the traffic at 90º to the road or in line with traffic into incoming or outgoing traffic. Pointing the radar at an angle substantially different from 90º or 0º is not recommended because the signal strength is severely reduced. The industry refers to pointing the radar at 90º as a side firing installation while pointing the radar in line with traffic is known as a front firing installation.
You MUST issue the “Initialize Clutter” command via the provided GUI after you have setup the radar in the intended location. You MUST reissue this command if you change the operating mode of the radar, as the clutter map will be considerably different. You MUST reissue this command after you adjust the radar pointing, height or angle on the road. Do NOT issue “Initialize Clutter” command on a periodic basis (e.g. every hour). First, this is not necessary.
Operating Modes The radar can be configured to function in different operating modes that are optimized for various applications. Current firmware supports two pre-programmed modes: “Highway” and “Intersection”. For the best performance an appropriate mode should be selected by the user depending on their intended application.
User Configurable Detection Lanes Lane Definition A lane is a user-configurable range slot within the radar’s detection zone. When a vehicle is present within this slot, the lane gets “activated”. Lane activations are used for presence indication whereas vehicle tracking is used for counting. For example if a vehicle has crossed from lane to lane it will be counted once only but both lanes will be sequentially activated.
If you have a controller board connected to the serial port of the radar, you may also obtain lane-by-lane target presence and other lane information in real-time. Historical Lane Counts As of radar firmware v124 and higher (release date May 10th 2012) the radar also counts the number of vehicles detected in each lane during every accumulation interval. Accumulation interval is programmed in minutes via BN variable. These counts are stored in internal memory and may be retrieved later for analysis.
across the radar detection zone, these combined calculations will result in a range reading that will vary materially more than the specified resolution of the radar. That said, the range resolution enhancement algorithm is able to achieve significantly better effective range measurement as compared to competing products. In many cases as much as 5 to 10x better performance can be expected.
Internal Clock The radar has a built in clock/calendar function. This is used to keep the time for time stamping historical records saved by the Advanced In-Radar traffic statistics collection feature. Because the radar is potted it does not feature a built-in clock backup battery. The power must remain on for the clock to keep time. However an external clock battery may be connected to keep time while radar goes into low power sleep mode. See Appendix C for more details.
Streaming ASCII Data Besides lane status streaming over binary protocol, the radar may be programed to stream certain types of data in ASCII format on its own, without receiving any further requests from the user. The output is produced on a periodic or event driven basis. The following data types are supported: Per lane counts on periodic basis. Output period in seconds is programmed by TA configuration variable. In order to enable streaming of counts, set bit 10 in MO variable.
1. Set MD variable to value 0+2^6=64 set:MD 64 OK 2. Observe radar output. You will see LN printouts every time the radar detects a vehicle in lane N (N=1..6).
Radar Mounting Beam pattern and enclosure PD420 and PD420 radars feature asymmetric beam patterns and can be supplied in either open frame or weatherproof version. Your intended application will determine the choice of the case type, beam pattern and beam rotation. The wider beam angle in PD420 is oriented differently from wider angle of the PD420. Make sure the orientation of the radar matches the one specified for your radar type.
Mounting Bracket Mounting bracket should allow for sufficient adjustment of the radar pointing angle and height. At the very minimum some degree of adjustment for the vertical angle should be provided. The user must perform a “boresight” check to validate that the radar beam is pointed correctly. Adding a guide fixture to facilitate boresight check is a good idea. If boresighting is not feasible you may choose to provide means to temporarily attach an inexpensive USB camera for the initial setup.
PD420 with vertical angle of 45º or PD420 with vertical of 60º Number of 12 Minimum Setback (ft) Minimum Setback (m) feet (4m) lanes Highway/Intersection Highway/Intersection 12 6 1.8 2 10 3.0 3 13 4.0 4 15 4.6 5 17 5.2 6 20 6.1 Minimum Height (ft) 4 17 17 20 21 23 Minimum Height (m) 1.2 5.2 5.2 6.1 6.4 7.0 Hookup Power Input: The PD420 radar features wide operating input voltage range of 5.5V-18V.
communication parameters are factory set to the following defaults: 115200 baud, 8 data bit, 1 stop bit and no parity. This configuration may be changed by user to some other appropriate combination. However, be aware that when target streaming is enabled the radar sends out massive amounts of data that cannot be transferred with low baud rate. Target streaming is automatically enabled by Configuration Utility during lane setup to visualize target tracks.
Note3: O/P 4 output is not available in units that have the “SYNC” option. Instead this pin is used to synchronize master and slave units.
Initial Setup You must initially configure the radar for your intended application at the installation site to ensure proper operation. At least an appropriate application mode and clutter time constant should be selected, clutter map initialized and lanes defined.
Selecting an Operating Mode Use provided Windows Configuration Utility to set an appropriate mode of operation as recommended in Operating Mode section. Use Highway Mode where precise counting of the vehicles is important. Use Intersection Mode where reliable detection of the stopped or slow moving traffic is important Selecting Clutter Time Constant and Performing Clutter Initialization Use provided Windows Configuration Utility to set clutter time constant (CTC).
Houston Radar PD420 User Manual Optimal Performance Checklist Radar should be not used in enclosure that would block microwave radiation, e.g. metal case. Some plastic and glass enclosures may too degrade the performance. Tunnel and under overpass locations should be avoided. The radar should be rigidly mounted to minimize wind action.
Synchronizing Multiple Radars When multiple radars are co-located it may be necessary to synchronize their frequency sweeps. If this functionality is desired, please order the radars with the “sync” option. When ordered with this option, digital output 4 is utilized for SYNC purposes and is not available as an open drain trigger output. The corresponding pins of the master and slave radars must be connected together via an external harness for the master to send a sync signal to the slave(s).
Using Windows Configuration Utility 1. Install the provided Houston Radar Advanced Stats Analyzer (or Houston Radar Configuration Tool) program on a Windows 2000, XP, Vista or Win 7 computer. 32 and 64 bit computers are supported. 2. Connect the radar RS232 port to the PC’s RS232 serial port. If the PC does not have a serial port you may use a USB to serial converter dongle. These dongles are readily available from BestBuy, Radioshack and many Internet stores. 3. Power up the radar.
Houston Radar PD420 User Manual PD420 Basic Application Setup STEP #1: Select Application Mode and background clutter adjustment time constant. See the section on clutter map earlier for a detailed explanation of this setting. After connecting to the radar, click on the PD420 Setup tab. The GUI will read the current radar configuration and allow you to edit and save it. Click on “Save Changes” to save the settings to the PD420. STEP #2: Initialize clutter to correct startup value.
PD420 Target Verification and Lane Setup STEP #3: Check target signal strength and location on the real time range plot. After selecting the application (“Highway” or “Intersection”) and initializing the background clutter map in the PD420 Setup Tab, click on the “PD420 Plot” tab. This will bring up a real time “chart recorder” type plot of tracked targets as shown below. Select the “PD420 Plot” window. Target linear range from face of the radar. Select how much history (in seconds) is shown on the chart.
Check Target Signal Strength: A very weak target. Only 5 empty RSS bars. Will be first to fade away into background clutter. Targets are plotted in real time as red lines and scroll from the right to the left. Long lines as shown represent stationary targets (this plot was taken inside a room. Some of the top targets are double reflections from walls and corners). Check “Show RSS” to show the target Receive Signal Strength. 3 or more solid bars out of 5 represent a good signal.
Excellent return signal strength from this vehicle on the road. Enable “Show Histograms” to observe where targets are appearing on the range plot. This will help you define lanes. Typical Real Time Chart Recorder View of “Highway Mode” Targets observed in the last 5 seconds show up as red tracks while older targets that have already scrolled off the screen are contributing to the height of the blue histograms on the screen left.
PD420 Live Lane Setup Step-By-Step Example: Real targets are streaming by. Setting up lanes is as easy as drawing around them on this chart. Right click on chart background to access lane setup context menu. Then select either “Define new Lane” if no lanes are present or “Edit Lane(s)…” if lanes have already been defined and you need to adjust the start/end positions. You can also draw around the built up histograms that show you where the targets are occurring.
PD420 Live Lane Setup Step-By-Step Example Continued… This road has 4 lanes (gray) with a median in between (white). Even though targets (sometimes double reflections or a curb or a lane divider) may be detected as red line in the median, they will not affect lane counts or other lane based data collected by the radar or trigger digital outputs. You can adjust the lane locations, add or delete a lane) by right clicking and selecting “Edit Lanes…” and bringing up this window.
In-Radar Lane-By-Lane Counts Both PD420 and PD420 can keep date/time stamped accumulated counts of vehicles in each lane and periodically save off this data in internal non-volatile memory. The PD420 radar with the 20x60 degree beam angle is suggested for best count accuracy. This minimizes the merging of the target return signal of closely following vehicles in far lanes where the radar beam has diverged past the width of a typical car. There is adequate memory to save the last 4+ months of data.
Reading Historical Counts Out Of The Radar: Ensure the stats package says “Enabled”. If not, then contact Houston Radar for a firmware upgrade as older versions of the firmware did not support saving historical logs of lane-by-lane counts. Once you connect to the radar, these buttons will become active and you can use them to erase the stats log memory, set the time in the radar and reads historical lane-by-lane counts from the radar memory. One the data is read from the radar it is stored as a native .
PD420 SPECIFICATIONS General Operating Band Occupied Bandwidth RF Power Output Max Range Range Resolution Polarization Supply Voltage Reverse Battery Power Consumption Nominal Current @12V Operating Temp. K-Band 24.020 GHz to 24.230 GHz 5mW 250 feet in Highway mode, 80 feet in Intersection Mode 0.375 inch in Highway Mode, 0.25 inch in Intersection Mode Linear 5.5V DC to 18V DC Protected 0.
Houston Radar PD420 User Manual Appendix A: Using trigger outputs The radars feature six low impedance “open drain” outputs that can trigger/turn on an external device when a vehicle is detected in a combination of user defined lanes. When a vehicle is detected in a lane and this lane is mapped to a trigger output, that output is pulled down to GND and held low as long as a vehicle is tracked in that lane. The output is released when the radar detects no further targets in that lane.
Houston Radar PD420 User Manual +Vhead Load Method 1 +Vhead Load rated to draw max of 150mA at +Vhead max Load Resistor Page 38 of 46 Load Method 2
Houston Radar PD420 User Manual Appendix B: Optional Breakout Board Non-Isolated Mosfet version with PWM Brightness Control. May be used with PD420 or SS300 radars. Light Sensor and brightness control is applicable only to the SS300 radar. Connecting the load to the High power and trigger outputs: You may directly connect your high power DC load + & - to J5. The load is activated via fuse F1 when the output is triggered.
Houston Radar PD420 User Manual Isolated Solid-State Relay version, AC or DC capable. May be used with PD420 or SS300 radars Optional Isolated IO Board. Note: PWM Brightness Control is NOT available with Isolated AC/DC Relay outputs.
Appendix C: Keeping Time With an External Clock Backup Battery Note: Current firmware does not support sleep mode. An update will be issued to address this issue. The content of this appendix may change depending on the implementation. The In-Radar traffic statistics generates time-stamped historical records that are saved in the on-board FLASH memory. Hence, the radar needs to keep calendar date and time.
Houston Radar PD420 User Manual Note 1: Connecting a RS232 cable to the radar or forcing the RS232 interface to ON does not affect the sleep power usage. Note 2: The radar power usage is approximately constant regardless of the input supply voltage in the sleep region. This is different when the radar is in the operational region where is behaves as a constant power device (current goes down with increasing voltage).
Houston Radar PD420 User Manual Appendix D: Recommended Enclosure for Open Frame Radars The PD420-OFD/PD420-OFD open frame radar needs to be enclosed in a weatherproof enclosure for outside use. The following needs to be observed for optimal performance: 1. The front face of the radar (PCB with the golden pads) is the antenna and is the face that must point towards traffic. 2. Any cover or window in front of the unit MUST be at least ¼” away from the face. 3.
Houston Radar PD420 User Manual Appendix E: ASCII Interface Some of the radar features can be accessed from ASCII command line interface over the serial port. For example all the radar variables can be set and queried in this fashion. ASCII commands may be issued via an ASCII terminal program like Hyperterminal or Teraterm Pro. Alternatively, you may issue these commands from an attached microcontroller.
Houston Radar PD420 User Manual sets the low speed cutoff to 5 etc. Note: Variables are case sensitive. Commands are not. Success is indicated by an "OK". Failure is indicated by either: "ERROR" - Command was recognized but some other error occurred, e.g. variable not present, format not correct, etc. - Command was not recognized. Entire line was silently discarded.
Houston Radar PD420 User Manual HO - hold C1...C6 O1...O6 S1...
