ACEINNA INS401 GNSS-RTK Navigation System Instruction Manual

INS401 GNSS-RTK Navigation System
Instruction Manual

INS401 EVK Introduction

The INS401 Evaluation Kit (EVK) is designed to evaluate the INS401 module with Aceinna toolAceNav.exe. A full set of INS401 EVK is shown below after you unpack the product box. Our target is quick running on your side with a PC.

Figure 1 Typical INS401 Connection System

Include:

1. Unit of INS401
2. Multi-Constellation and Multi-frequency GNSS antenna supports
3. Wire harness connector
4. 12 V DC Adapter with 5.5 mm x 2.1 mm Jack
5. 100Base-TX to 100Base-T1 Converter (3-ETH_TRX_N-, 4-ETH_TRX_P+)
6. Ethernet cable

If no EVK on your side, below parts, need to be prepared by yourself:

• Mating harness connector
  Part number MX23A18SF1 from JAE Electronics

• 100base-T1/TX converter board
  Part number EV02N47A – EVB-LAN8770_MC from MICROCHIP

Prerequisites

HW

A typical configuration of the INS401 is shown in Figure 1. The circular RF connector connects with an active GNSS antenna, and the main MX23A connector contains the connection with the external power, the ethernet data cable, and the other communication port cable if needed.
The primary data port is the automotive-grade Ethernet port to connect to a vehicle ECU directly or to a testing computer via a converter.
Figure 1 shows a test setup only with a testing PC, which requires a key unit and the 100BaseTX (with RJ-45 connector) to 100Base-T1 converter (3-ETH_TRX_N-, 4- ETH_TRX_P+), to connect an automotive-grade Ethernet device within industrial ethernet device typically seen on a computer.
Pls note: FW version of INS401 is equal to or larger than 28.02, pls refer to the information (FW/Bootloader version) about INS401

SW

OS: take Windown10 as an example.
“AceNav” is open sourced on Aceinna/acenav-(GitHub.com) and executables download link: https://github.com/Aceinna/acenav-cli/releases
Npcap download link (need to be installed): https://navview.blob.core.windows.net/forum/upload/npcap-1.55.exe- kv7fw14u.zip
User manual for your reference: https://www.aceinna.com/inertial- systems/INS401

Configurations used

Default parameters as below, no need to update it if only for simple function testing

Parameter ID| Name| Unit| Description| Current value used
---|---|---|---|---
1| gnssLeverArmBx| m| IMU to GNSS antenna phase center lever arm| 1.
2| gnssLeverArmBy| m| 0.
3| gnssLeverArmBz| m| -1.
4| vrpLeverArmBx| m| IMU to vehicle reference point lever arm| o
5| vrpLeverArmBy| m| 0
6| vrpLeverArmBz| m| o
7| userLeverArmBx| m| The offset between IMU to the user point of interest (which position is output in INS packets of INS401)| 1.
8| userLeverArmBy| m| 0.
9| userLeverArmBz| m| -1.
10| rotation box| deg| Rotation angles to align IMU body| 0
11| rotation by| deg| frame to vehicle frame, in order
Z->Y->X| 0
12| rotationRbvz| deg| 0

* INS401(see user manual) is the origin point under the vehicle coordinate system. And X/Y/Z of
INS401 Axis pls refer to 3.1 Orientation.
The odometer is not used now, and pls refer to the Configuration of the odometer when using it.

Usage steps

Setup

Mount the INS401 on a flat rigid panel in the vehicle, align the x-axis with the forward driving direction of the vehicle
The recommended coordinate system is that X is facing forward, Y is right and Z is down when mounting, let’s use the orientation for the quick star. Pls, refer to Configuration of orientation if a new orientation is used.

Figure 2 IMU Axis Definition and Navigation Center Location

Mount the antenna to a secure, stable structure with a clear view of the sky
Connect the antenna to the FAKRA RF terminal
Connect the wire harness connector to the main the connector of the INS401
Use the ethernet cable to connect the ethernet converter to the ethernet port on the PC
Connect the jack from the wire harness to the 12 V power adapter and connect the power adapter to a power supply

Running Steps and Data Logging

1. In the “AceNav” folder, modify the “ins401.json” JSON file inside the “settings/INS401” subfolder, input the correct NTRIP account information as shown below:
   

2. Update values for ID (1-12) based on Configurations used.
   

3. After the “ins401.json” file is updated, to make it effective, run AceNav.exe with the “-s” option as below, and succussed when “Success (12)” is displayed on the console.
   .\acenav.exe -i 100base-t1 -s
   

4. Power reset INS401 and run AceNav.exe, the information (FW/Bootloader version) about INS401, the PC connection, and the NTRIP connection status will be displayed on the console. The NTRIP status shows “ok” of both [connect] and [request], then the system has connected to a valid NTRIP server for the GNSS RTK operation
   

5. Check the output bin files. Every session the “AceNav” has started, a data log subfolder with the time tag in the folder name is created under “acenav/data”. The data log  subfolder for each data logging session contains four files:
   • configuration.json: INS401 configuration file read from the device flash
   • rtcmbase.bin: GNSS RTK correction data in RTCM format
   • rtcmrover.bin: INS401 GNSS raw data in RTCM format
   • user_.bin: positioning solution, raw IMU and other related variance/status information shown in #6
   • inssave.bin: save last status of INS401 when power was off
   

6. Run the data parsing command to get engineering data from the “user_bin” file
   

7. Check the decoded files for results representation and analysis
   • user_dm.csv: INS401 system diagnostic messages
   • usergnss.csv: GNSS solution at 1 Hz
   • userimu.csv: raw IMU data at 100 Hz
   • userins.csv: INS solution at 100 Hz
   • usergnss.kml: GNSS solution trajectory in kml format
   • userins.kml: INS solution trajectory in kml format
   • usernmea.txt: GNSS solution in NMEA 0183 ASCII
   • user_odo.txt: vehicle odometer speed data received by INS401
   

Backup

Configuration of orientation

No need to update orientation, if we mount INS401 same recommended direction.
Pls, update the below rotation parameters to re-align with forwarding/right/down, if your mounting is different.

vehicle frame, in order Z->Y->X when rotated
11| float| rotation by| deg
12| float| rotationRbvz| deg

X/Y/Z of INS401 Axis pls refer to 3.1 Orientation.
Below table for your reference:

INS401 Axis

| X| Y| Z|

Rotation X/Y/Z

---|---|---|---|---

1 Recommended

| Forward| Right| Down| 0, 0, 0
2| Forward| Left| Up|

180, 0, 0

3

| Forward| Down| Left| -90.0, 0, 0
4| Forward| Up| Right|

90.0, 0, 0

5

| Backward| Left| Down| 0, 0, 180.0
6| Backward| Right| Up|

0, 180.0, 0

7

| Backward| Up| Left| -90.0, 0, 180.0
8| Backward| Down| Right|

90.0, 0, 180

9

| Right| Backward| Down| 0, 0, -90.0
10| Right| Forward| Up|

180, 0, -90.0

11

| Right| Up| Backward| 90.0, 90.0, 0
12| Right| Down| Forward|

0, -90.0, -90.0

13

| Left| Forward| Down| 0, 0, 90.0
14| Left| Backward| Up|

180.0, 0, -90.0

15

| Left| Up| Forward| 0, -90.0, 90.0
16| Left| Down| Backward|

-90.0, 90.0, 0

17

| Up| Forward| Left| -90.0, 0, 90
18| Up| Backward| Right|

90.0, 0, -90.0

19

| Up| Right| Forward| 0, -90.0, 0
20| Up| Left| Backward|

0, 90.0, 180.0

21

| Down| Forward| Right| 90.0, 0, 90.0
22| Down| Backward| Left|

-90.0, 0, -90.0

23

| Down| Left| Forward| 0, -90.0, 180.0
24| Down| Right| Backward|

0, 90.0, 0

Configuration of the antenna lever arm

After the INS401 is mounted to the vehicle, measure the IMU to the GNSS antenna lever arm (translational offset) from the IMU navigation center to the GNSS antenna phase center. The GNSS antenna is typically installed on top of the vehicle roof. For optimal performance, it is required to have a lever arm accuracy of less than 2 cm.
For instance, a lever arm measurement is shown in the figure below. The translation offset is measured as 1 m in each direction of x, y, and z. The IMU to the GNSS antenna lever arm  is [x, y, z] = [1.0, -1.0, -1.0] m. The “Set User Configuration” command should be used to configure the INS401 with the correct lever arm.

Configuration of the interesting point lever arm

The interesting point is the position that will be output in the INS packet, so we need to configure the target position corresponding to the origin point of INS401.
Generally, the interesting point is the antenna or odometer reference points.

Configuration of odometer reference point

1. Confirm Odometer enabled
   Pls, refer to “Get User Configuration” command in the user manual, and check the status of ID13.
   It is enabled by default, pls ignore this step if no change before.

2. Measure distances from INS401 to odometer reference point

3. Update the input value Configurations used

4. Send speed value to INS401 with 100base-T1 protocol:
   Example:Speed values| Packets
   ---|---
   39.5km/h| 01 02 03 04 05 06 06 05 04 03 02 01 00 0e 55 55 01 0b 04 00 00 00 00 00 1e 42 a8 90 00 00 00 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   -11.5km/h| 01 02 03 04 05 06 06 05 04 03 02 01 00 0e 55 55 01 0b 04 00 00 00 00 00 38 c1 a5 3b 00 00 00 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

5. Confirm odometer is used in INS401, there 2 ways to verify
   • In step9 from 3.2, check whether user_odo.txt is existed in decoded files
   • Check 0x0a04 msg in 100base-T1 net or not, tools recommended: Wireshark.exe

References

• GitHub: Let’s build from here · GitHub
• GitHub - Aceinna/acenav-cli: Aceinna Navigation System Command Line Interface software
• Releases · Aceinna/acenav-cli · GitHub
• INS401 - Aceinna: Leader in MEMS Sensor Technology

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