The bus parking challenge
Public transportation has been hit by a shortage of drivers, not just in ride-hailing fleets, but also in municipal buses and shuttles. In the current state of the market, there is a shortage of city bus drivers as the job is considered laborious, repetitive, and not particularly well-paid. This leads to significant turnover as experienced drivers are resigning while it takes time to train new workers with the skills to operate the buses safely and efficiently. Driving an articulated “tandem” bus requires a certain level of experience, especially when performing maneuvers in narrow areas like bus depots where buses are squeezed to fit as many vehicles as feasible in a confined space.
Parking assistance systems for bus operators
To reduce the likelihood of driving incidents related to the skilled driver shortage, Poznan University of Technology in Poland collaborated with Solaris Bus and Coach to develop an intelligent Advanced Driver Assistance System (ADAS) for parking and other difficult driving scenarios. The driver assist functionality of the system helps guide the driver during parking maneuvers, helping to reduce the number of incidents while simultaneously teaching the driver the desired behavior and skills. With this technical assistance, driving an articulated bus can be made safer for new drivers which lack the requisite experience. The system can map out the complete parking maneuver from the current position of the vehicle to the desired parking slot, providing steering cues to the driver along the way as they navigate the vehicle forward or backward into a narrow spot.
The need for 3D perception
Any ADAS performing parking maneuvers requires proper sensing of the surrounding environment. The Ouster OS1-128 was selected for its ability to provide range measurements up to 120 meters and for its high-resolution 3D view of the environment. The OS1-128 sensor is mounted on top of the front of the bus. To enable safe reverse maneuver capabilities, another OS1 was mounted on the rear of the long vehicle. The point cloud generated by Ouster’s digital lidar is utilized for two purposes: to localize the bus and to create a detailed view of the environment.
The system takes into account the bus model form-factor and mechanics and computes steering directions which are shown to the bus driver (see image below). The bus driver is able to control the speed of the maneuver as they are directed to follow the steering directions, facilitating a safer, more accurate parking maneuver. The system is able to recalculate the path in real-time, guiding the driver if he or she deviates from the recommended course.
While more needs to be done to fully understand the cost benefits enabled by park assistance, the system developed by the Poznan University of Technology together with Solaris Bus & Coach is a step towards improving driver safety, advancing the autonomy of buses, and improving the economics of public transportation in cities across the globe.
References
[1] M. M. Michalek, T. Gawron, M. Nowicki, P. Skrzypczynski, Precise Docking at Charging Stations for Large-Capacity Vehicles: An Advanced Driver-Assistance System for Drivers of Electric Urban Buses, IEEE Vehicular Technology Magazine, vol. 16, no. 3, pp. 57-65, 2021
[2] K. Cwian, M. Nowicki, J. Wietrzykowski, P. Skrzypczynski, Large-Scale LiDAR SLAM with Factor Graph Optimization on High-Level Geometric Features, Sensors, Vol. 21, No. 10, 3445, 2021
