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A Mobility-Aware Adaptive Duty Cycling Mechanism for Tracking Objects during Tunnel Excavation

View Article: PubMed Central - PubMed

ABSTRACT

Tunnel construction workers face many dangers while working under dark conditions, with difficult access and egress, and many potential hazards. To enhance safety at tunnel construction sites, low latency tracking of mobile objects (e.g., heavy-duty equipment) and construction workers is critical for managing the dangerous construction environment. Wireless Sensor Networks (WSNs) are the basis for a widely used technology for monitoring the environment because of their energy-efficiency and scalability. However, their use involves an inherent point-to-point delay caused by duty cycling mechanisms that can result in a significant rise in the delivery latency for tracking mobile objects. To overcome this issue, we proposed a mobility-aware adaptive duty cycling mechanism for the WSNs based on object mobility. For the evaluation, we tested this mechanism for mobile object tracking at a tunnel excavation site. The evaluation results showed that the proposed mechanism could track mobile objects with low latency while they were moving, and could reduce energy consumption by increasing sleep time while the objects were immobile.

No MeSH data available.


System model for tracking objects in tunnel excavation.
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sensors-17-00435-f005: System model for tracking objects in tunnel excavation.

Mentions: In clustering based protocols, for example LEACH [25], nodes make groups with their neighbors and direct the data of member nodes to a leader node called the cluster head, to reduce the amount of data that must be transmitted to the base station. This is because it is impossible and inefficient for all sensor nodes to communicate with the base station directly. Cluster heads near the base station consume more energy than other cluster heads due to a bottleneck in the data traffic. This problem can be solved by using advanced routing protocols [26,27]. Each cluster head (CHi) is connected with two neighbor cluster heads (CHi−1, CHi+1) and gathers data of the mobile sensors (member nodes) within its communication range r, as shown in Figure 5. If the mobile sensor changes its location as marked by the movement vector v and cannot communicate with the old cluster head (CHi), a new cluster head (CHi+1) that can communicate with the mobile sensor enrolls and manages the mobile sensor. In terms of mobile sensors, their movement determines their sleep time. Each node is defined as in a non-mobility state if and only if its change of RSSI value () is less than the threshold ; whereas the mobility state implies the opposite. A sensor in a mobility state () decreases its sleep time to frequently send its state information to the cluster head; whereas, a mobile sensor in a non-mobility state (), increases its sleep time to rarely send its state information to the cluster head. For example, as shown in Figure 4, the dump truck stopped to load mucks corresponds to the latter, and the pay loader that travels back and forth between muck and the dump truck corresponds to the former.


A Mobility-Aware Adaptive Duty Cycling Mechanism for Tracking Objects during Tunnel Excavation
System model for tracking objects in tunnel excavation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5375721&req=5

sensors-17-00435-f005: System model for tracking objects in tunnel excavation.
Mentions: In clustering based protocols, for example LEACH [25], nodes make groups with their neighbors and direct the data of member nodes to a leader node called the cluster head, to reduce the amount of data that must be transmitted to the base station. This is because it is impossible and inefficient for all sensor nodes to communicate with the base station directly. Cluster heads near the base station consume more energy than other cluster heads due to a bottleneck in the data traffic. This problem can be solved by using advanced routing protocols [26,27]. Each cluster head (CHi) is connected with two neighbor cluster heads (CHi−1, CHi+1) and gathers data of the mobile sensors (member nodes) within its communication range r, as shown in Figure 5. If the mobile sensor changes its location as marked by the movement vector v and cannot communicate with the old cluster head (CHi), a new cluster head (CHi+1) that can communicate with the mobile sensor enrolls and manages the mobile sensor. In terms of mobile sensors, their movement determines their sleep time. Each node is defined as in a non-mobility state if and only if its change of RSSI value () is less than the threshold ; whereas the mobility state implies the opposite. A sensor in a mobility state () decreases its sleep time to frequently send its state information to the cluster head; whereas, a mobile sensor in a non-mobility state (), increases its sleep time to rarely send its state information to the cluster head. For example, as shown in Figure 4, the dump truck stopped to load mucks corresponds to the latter, and the pay loader that travels back and forth between muck and the dump truck corresponds to the former.

View Article: PubMed Central - PubMed

ABSTRACT

Tunnel construction workers face many dangers while working under dark conditions, with difficult access and egress, and many potential hazards. To enhance safety at tunnel construction sites, low latency tracking of mobile objects (e.g., heavy-duty equipment) and construction workers is critical for managing the dangerous construction environment. Wireless Sensor Networks (WSNs) are the basis for a widely used technology for monitoring the environment because of their energy-efficiency and scalability. However, their use involves an inherent point-to-point delay caused by duty cycling mechanisms that can result in a significant rise in the delivery latency for tracking mobile objects. To overcome this issue, we proposed a mobility-aware adaptive duty cycling mechanism for the WSNs based on object mobility. For the evaluation, we tested this mechanism for mobile object tracking at a tunnel excavation site. The evaluation results showed that the proposed mechanism could track mobile objects with low latency while they were moving, and could reduce energy consumption by increasing sleep time while the objects were immobile.

No MeSH data available.