A Low-Cost Underground Garage Navigation Switching Algorithm Based on Kalman Filtering

Abstract

Modern parking lots have gradually developed into underground garages to improve the efficient use of space. However, the complex design of parking lots also increases the demands on vehicle navigation. The traditional method of navigation switching only uses satellite signals. After the Position Dilution Of Precision (PDOP) of satellite signals is over the limit, vehicle navigation will enter indoor mode. It is not suitable for vehicles in underground garages to switch modes with a fast-response system. Therefore, this paper chooses satellite navigation, inertial navigation, and the car system to combine navigation. With the condition that the vehicle can freely travel through indoor and outdoor environments, high-precision outdoor environment navigation is used to provide the initial state of underground navigation. The position of the vehicle underground is calculated by the Dead Reckoning (DR) navigation system. This paper takes advantage of the Extended Kalman Filter (EKF) algorithm to provide two freely switchable navigation modes for vehicles in ground and underground garages. The continuity, robustness, fast response, and low cost of the indoor and outdoor switching navigation methods are verified in real-time systems.

Indoor and Outdoor Low-Cost Seamless Integrated Navigation System Based on the Integration of INS/GNSS/LIDAR System

“…The switching the navigation algorithm is the connecting part of the above two integrated navigation modes, and it is also a relatively difficult part to handle. This paper cites the indoor and outdoor navigation switching algorithm found in [25,27]. After inheriting the above switching algorithm, this paper also conducts secondary development.…”

“…If the vehicle does not enter the descending ramp after a certain period of time and the GNSS satellite navigation signal is stable, the pre-switching status of navigation system will be canceled. When the navigation system is the pre-switching state, if the pitch angle θ c of the vehicle is less than half of the steering angle after a period of time, the underground garage tilt angle θ g minus the equipment installation angle θ f , or obvious GNSS data packet loss or disconnected, that is, the satellite Pulse Per Second (PPS) stops counting or the Position Dilution Of Precision (PDOP) positioning accuracy parameter is less 7, as shown in Equation (27). When Equation (27) meets any of the three conditions, it means that the vehicle has entered the entrance of the underground garage.…”

“…Figure 3. The first experiment conducted the simulated ramp experiment in garage gate, and compared with the experiment in [27] to verify whether the simulated robot platform can realize the switching algorithm of commercial vehicles or not. In addition, when the navigation system is supplement with the laser scanner signal, the stability and reliability of the system are verified in the meantime.…”

A Low Cost Civil Vehicular Seamless Navigation Technology Based on Enhanced RISS/GPS between the Outdoors and an Underground Garage

“…Nevertheless, we still need GPS parameters to make further judgement. When the position dilution of precision (PDOP) of the system reaches a low range and the satellite pulse per second (PPS) stops counting, the switching algorithm works, and the DR algorithm of the vehicle can run a stable and accurate trajectory in the underground garage [7]. This judgement process is reflected in Equation 13.…”

“…Therefore, the integration of satellite navigation and inertial navigation is the preferred method for connecting indoor and outdoor positioning [6]. When the system has the full inertial measurement unit (IMU) inertial navigation mode with a tri-axial gyroscope, tri-axial accelerometer and tri-axial magnetometer, the system can use the extended Kalman filter (EKF) for combined navigation with GPS satellite data and nine axis inertial sensor data [7]. However, due to some requirements such as those for civil vehicles, which should have a rigorous cost saving control for market competition, the traditional full inertial navigation system (INS)/GPS integrated navigation scheme will become less important.…”