Study of the Emergency Braking Test with an Autonomous Bus and the sEMG Neck Response by Means of a Low-Cost System

Toro, Sergio Fuentes del; Santos-Cuadros, Silvia; Olmeda, Ester; García, José Luis San Román

doi:10.3390/mi11100931

Cited by 6 publications

(4 citation statements)

References 101 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Firstly, all the signals were synchronised and after the sEMG timed, filtrated, and normalised. More information about the synchronisation can be found in [ 20 ], where all the steps in the process were carefully explained.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?

Santos-Cuadros

Toro

Olmeda

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

Deaths and serious injuries caused by traffic accidents is a concerning public health problem. However, the problem can be mitigated by the Autonomous Emergency Braking (AEB) system, which can avoid the impact. The market penetration of AEB is exponentially growing, and non-impact situations are expected to become more frequent. Thus, new injury patterns must be analysed, and the neck is particularly sensitive to sudden acceleration changes. Abrupt braking would be enough to be a potential risk for cervical spine injury. There is controversy about whether or not there are differences in cervical behaviour depending on whether passengers are relaxed or contract their muscles before the imminent accident. In the present manuscript, 18 volunteers were subjected to two different levels of awareness during an emergency braking test. Cervical muscles (sternocleidomastoid and trapezius) were analysed by the sEMG signal captured by means of a low-cost system. The differences observed in the muscle response according to gender and age were notable when passengers are warned. Gender differences were more significant in the post-braking phase. When passengers were relaxed, subjects older than 35 registered higher sEMG values. Meanwhile, when passengers contract their muscles, subjects who were younger than or equal to 35 years old experienced an increment in the values of the sEMG signals.

show abstract

Section: Methodsmentioning

confidence: 99%

“…PM: Position Markers, HSC: High-Speed Camera, AM: Accelerometer, sEMG: Sensors of Surface Electromyography. Based on [ 20 ].…”

Section: Figurementioning

confidence: 99%

Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?

Santos-Cuadros

Toro

Olmeda

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

show abstract

“…The subjects were supposed to be relaxed before braking since they were unaware of the instant of braking. Signal normalization of the sEMG signals was conducted based on mean activation levels obtained during the task, as explained in ( Pons et al, 2013 ; Del Toro et al, 2020 ). • Step 4: Initial posture standardization.…”

Section: Methodsmentioning

confidence: 99%

Kinematic analysis of an unrestrained passenger in an autonomous vehicle during emergency braking

Santos-Cuadros,

Page del Pozo,

Álvarez-Caldas

et al. 2024

Front. Bioeng. Biotechnol.

Self Cite

View full text Add to dashboard Cite

Analyzing human body movement is a critical aspect of biomechanical studies in road safety. While most studies have traditionally focused on assessing the head-neck system due to the restraint provided by seat belts, it is essential to examine the entire pelvis-thorax-head kinematic chain when these body regions are free to move. The absence of restraint systems is prevalent in public transport and is also being considered for future integration into autonomous vehicles operating at low speeds. This article presents an experimental study examining the movement of the pelvis, thorax and head of 18 passengers seated without seat belts during emergency braking in an autonomous bus. The movement was recorded using a video analysis system capturing 100 frames per second. Reflective markers were placed on the knee, pelvis, lumbar region, thorax, neck and head, enabling precise measurement of the movement of each body segment and the joints of the lumbar and cervical spine. Various kinematic variables, including angles, displacements, angular velocities and accelerations, were measured. The results delineate distinct phases of body movement during braking and elucidate the coordination and sequentiality of pelvis, thorax and head rotation. Additionally, the study reveals correlations between pelvic rotation, lumbar flexion, and vertical trunk movement, shedding light on their potential impact on neck compression. Notably, it is observed that the elevation of the C7 vertebra is more closely linked to pelvic tilt than lumbar flexion. Furthermore, the study identifies that the maximum angular acceleration of the head and the maximum tangential force occur during the trunk’s rebound against the seatback once the vehicle comes to a complete stop. However, these forces are found to be insufficient to cause neck injury. While this study serves as a preliminary investigation, its findings underscore the need to incorporate complete trunk kinematics, particularly of the pelvis, into braking and impact studies, rather than solely focusing on the head-neck system, as is common in most research endeavors.

show abstract

“…It should be noted that the threshold of acceleration that can be harmful depends on the subject. Gender, age, physical condition, and previous neck injuries, among other factors, may affect the behavior of the volunteer during braking as well [42].…”

Section: Design Of Experimental Testsmentioning

confidence: 99%

Experimental Validation of a Driver Monitoring System

Garrosa,

Ceccarelli,

Díaz

et al. 2023

Machines

View full text Add to dashboard Cite

This paper presents an analysis of the risk of neck injury in vehicle occupants as a consequence of an impact. A review of the formulation of indexes that are used in the assessment and investigation of neck injury risk is discussed with the aim of providing a new, more appropriate index using suitable sensorized equipment. An experimental analysis is proposed with a new driver monitoring device using low-cost sensors. The system consists of wearable units for the head, neck, and torso where inertial measurement sensors (IMU) are installed to record data concerning the occupant’s head, neck, and torso accelerations while the vehicle moves. Two laser infrared distance sensors are also installed on the vehicle’s steering wheel to record the position data of the head and neck, as well as an additional IMU for vehicle acceleration values. To validate both the device and the new index, experiments are designed in which different sensorized volunteers reproduce an emergency braking maneuver with an instrumented vehicle at speeds of 10, 20, and 30 km/h before the beginning of any braking action. The neck is particularly sensitive to sudden changes in acceleration, so a sudden braking maneuver is enough to constitute a potential risk of cervical spine injury. During the experiments, large accelerations and displacements were recorded as the test speed increased. The largest accelerations were obtained in the experimental test at a speed of 30 km/h with values of 19.17, 9.57, 9.28, and 5.09 m/s2 in the head, torso, neck, and vehicle, respectively. In the same experiment, the largest displacement of the head was 0.33 m and that of the neck was 0.27 m. Experimental results have verified that the designed device can be effectively used to characterize the biomechanical response of the neck in car impacts. The new index is also able to quantify a neck injury risk by taking into account the dynamics of a vehicle and the kinematics of the occupant’s head, neck, and torso. The numerical value of the new index is inversely proportional to the acceleration experienced by the vehicle occupant, so that small values indicate risky conditions.

show abstract

Study of the Emergency Braking Test with an Autonomous Bus and the sEMG Neck Response by Means of a Low-Cost System

Cited by 6 publications

References 101 publications

Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?

Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?

Kinematic analysis of an unrestrained passenger in an autonomous vehicle during emergency braking

Experimental Validation of a Driver Monitoring System

Contact Info

Product

Resources

About