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Figure 2:

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Figure 4:

Figure 5:

Figure 6:

Figure 7:

Figure 8:

The EKF parameter details_
| Parameter | Information |
|---|---|
|
| The estimated state |
| f | Non-linear model system |
| h | Measurement model system |
| vk | Measurement noise |
| zk | IMU measurement |
| Wk − 1 | Dynamic system noise |
|
| The estimated updates state |
| V | The linear velocity of the robot |
| Δt | Time derivative |
| θ | The steering angle of the robot |
| Qk | Dynamic system noise matrix
|
| Hk | IMU measurement matrix
|
| Rk | Measurement noise matrix
|
| Fk | Jacobians matrix,
|
The steps of the EKF-SLAM Algorithm_
| EKF-SLAM Algorithm |
|---|
|
The comparison of the encoder results and the reference in X-axis_
| X position from odometry | X reference | Error |
|---|---|---|
| 0.95 | 0.97 | 0.02 |
| 0.95 | 0.97 | 0.03 |
| 0.95 | 0.97 | 0.03 |
| 0.95 | 0.97 | 0.03 |
| 0.95 | 0.98 | 0.03 |
| 0.95 | 0.98 | 0.04 |
| 0.95 | 0.98 | 0.04 |
| 0.95 | 0.99 | 0.04 |
| 0.95 | 0.99 | 0.04 |
| 0.95 | 1.00 | 0.05 |
| Error in average (%) | 3 | |
The details of robot parameters_
| Parameter | Value |
|---|---|
| Battery | 12.6 V (DC) |
| Dimension | 242.9 × 192.2 mm |
| Steering servo | 9 kg/cm torque |
| Wheel motor | 240 RPM |
| Wireless | 2.4G/5G dual-band WIFI, Bluetooth 4.2 |
| Driving type | Ackerman steering dual gearmotor rear wheel drive |
Comparison between the EKF positions and the reference_
| X position (EKF) | X reference | Y position (EKF) | Y reference | Error X | Error Y |
|---|---|---|---|---|---|
| 0.97 | 0.97 | 0.02 | 0.02 | 0.00 | 0.00 |
| 0.98 | 0.97 | 0.02 | 0.02 | 0.01 | 0.00 |
| 0.98 | 0.97 | 0.02 | 0.02 | 0.01 | 0.01 |
| 0.98 | 0.97 | 0.02 | 0.02 | 0.01 | 0.01 |
| 0.99 | 0.98 | 0.02 | 0.02 | 0.01 | 0.02 |
| 0.99 | 0.98 | 0.02 | 0.02 | 0.01 | 0.04 |
| 1.00 | 0.98 | 0.02 | 0.02 | 0.02 | 0.04 |
| 1.01 | 0.99 | 0.02 | 0.02 | 0.02 | 0.04 |
| 1.01 | 0.99 | 0.02 | 0.02 | 0.02 | 0.04 |
| 1.02 | 1.00 | 0.02 | 0.02 | 0.02 | 0.05 |
| Error in average (%) | 1 | 3 | |||
| RMSE | 0.11 | 0.15 | |||
Accelerometer measurements_
| X | Y | X reference | Y reference | X error | Y error |
|---|---|---|---|---|---|
| 0.02 | −0.02 | 0 | 0 | 0.02 | −0.02 |
| 0.01 | −0.01 | 0 | 0 | 0.01 | −0.01 |
| −0.03 | −0.02 | 0 | 0 | −0.03 | −0.02 |
| −0.06 | −0.02 | 0 | 0 | −0.06 | −0.02 |
| −0.07 | −0.02 | 0 | 0 | −0.07 | −0.02 |
| −0.06 | 0.01 | 0 | 0 | −0.06 | 0.01 |
| −0.06 | −0.03 | 0 | 0 | −0.06 | −0.03 |
| 0.01 | 0.01 | 0 | 0 | 0.01 | 0.01 |
| −0.01 | 0.00 | 0 | 0 | −0.01 | 0.00 |
| −0.06 | −0.02 | 0 | 0 | −0.06 | −0.02 |
| Error in average (%) | 4 | 2 | |||
The maximum and minimum distance values of the LiDAR data_
| Maximum (m) | Minimum (m) | |
|---|---|---|
| Measured data | 6.808 | 0.15 |
| Actual value (reference) | 6.54 | 0.09 |
| Error (%) | 4 | 67 |
Gyroscope orientation measurements_
| X orientation | Y orientation | X reference | Y reference | X error | Y error |
|---|---|---|---|---|---|
| −0.01 | −0.01 | 0 | 0 | −0.01 | −0.01 |
| −0.01 | −0.01 | 0 | 0 | −0.01 | −0.01 |
| −0.01 | 0.02 | 0 | 0 | −0.01 | 0.02 |
| −0.01 | 0.03 | 0 | 0 | −0.01 | 0.03 |
| −0.01 | 0.03 | 0 | 0 | −0.01 | 0.03 |
| 0.00 | 0.03 | 0 | 0 | 0.00 | 0.03 |
| −0.01 | 0.03 | 0 | 0 | −0.01 | 0.03 |
| 0.00 | 0.00 | 0 | 0 | 0.00 | 0.00 |
| 0.00 | 0.00 | 0 | 0 | 0.00 | 0.00 |
| −0.01 | 0.03 | 0 | 0 | −0.01 | 0.03 |
| Errors in average (%) | 1 | 2 | |||
The comparison of the encoder results and the reference in Y-axis_
| Y position from odometry | Y reference | Error |
|---|---|---|
| 0.02 | 0.02 | 0.00 |
| 0.02 | 0.02 | 0.00 |
| 0.02 | 0.02 | 0.00 |
| 0.02 | 0.02 | 0.00 |
| 0.02 | 0.02 | 0.00 |
| 0.01 | 0.02 | 0.01 |
| 0.01 | 0.02 | 0.01 |
| 0.02 | 0.02 | 0.02 |
| 0.07 | 0.02 | 0.05 |
| 0.07 | 0.02 | 0.05 |
| Error in average (%) | 2 | |