The hardware performance of the G-sensor is fundamental to its sensitivity. As a core component for detecting changes in acceleration, the accuracy of the G-sensor directly determines its collision detection capability. High-quality G-sensors employ microelectromechanical systems (MEMS) technology, integrating micro-mechanical structures and circuits to accurately capture changes in vehicle acceleration in three-dimensional space. For example, when a vehicle collides, the G-sensor detects the displacement of the mass due to inertia and converts this physical signal into an electrical signal, transmitting it to the main chip of the car dash cam. If the G-sensor's sensitivity is insufficient, it may fail to detect minor collisions or low-speed vibrations, resulting in crucial video footage not being saved; conversely, if the sensitivity is too high, it may trigger false recordings due to everyday driving behaviors such as road bumps or sudden braking, consuming storage space.
The software algorithm's processing logic for G-sensor data is equally critical. The main chip of the car dash cam needs to filter, threshold, and respond to actions on the raw data transmitted from the G-sensor. For example, algorithms need to distinguish between bumps during normal driving and severe vibrations during collisions. By setting reasonable acceleration thresholds and durations, false triggers or missed recordings can be avoided. Some high-end car dash cams also employ multi-axis sensor fusion technology, combining data such as acceleration and angular velocity to improve collision detection accuracy. If the algorithm optimization is insufficient, even with excellent G-sensor hardware performance, a poorly processed data logic can lead to sensitivity imbalances.
The installation location and angle significantly impact collision sensing performance. Car dash cams should be installed in areas of minimal vehicle vibration, typically near the rearview mirror or above the center of the windshield, to minimize interference from engine vibrations or road bumps. If the installation location deviates from the vehicle's center of gravity (e.g., near a door or hood), larger local vibrations may cause false triggers. Furthermore, the lens angle must be parallel to the vehicle's direction of travel to avoid image distortion or collision detection deviation due to tilt. For example, if the lens is tilted downwards, it may only record ground information and ignore forward collisions, affecting sensitivity judgment.
Vehicle driving environments and driving habits impose different requirements on sensitivity settings. In bumpy roads or driving scenarios with frequent acceleration and deceleration, high sensitivity settings may result in a large amount of non-critical video being saved, requiring regular storage space cleanup. Conversely, on highways or in congested urban environments, low sensitivity may miss minor collisions or scrapes. Therefore, some car dash cams support tiered sensitivity adjustment (e.g., high, medium, and low), allowing users to choose flexibly based on actual road conditions and driving style. For example, long-haul trucks might choose medium sensitivity to balance recording needs and storage efficiency, while urban commuters might prefer high sensitivity to handle complex road conditions.
Storage space and video protection mechanisms indirectly affect the sensitivity experience. Car dash cams typically use a loop recording mode, where new videos overwrite older ones to save space. If the collision sensing sensitivity is too high, a large number of videos may be marked as "emergency protection," preventing them from being looped over and ultimately stopping recording due to insufficient storage space. Therefore, users need to regularly clean or format the memory card, or choose a device that supports emergency storage mode and use partition management to ensure that critical videos are not overwritten. For example, some car dash cams divide the memory card into a normal recording area and an emergency protection area. The former is cyclically overwritten, while the latter is permanently stored, thus optimizing the balance between sensitivity and storage space.
Temperature and heat dissipation conditions pose challenges to the stability of the G-sensor. Prolonged operation at high temperatures can cause sensor performance drift, reducing detection accuracy. For example, in hot summer weather or during long-distance driving, if the car dash cam lacks a heat dissipation design (such as ventilation holes or a metal casing), excessive internal temperature may cause a decrease in G-sensor sensitivity or false triggers. Therefore, choosing a device with heat dissipation capabilities or avoiding prolonged continuous use can maintain sensitivity stability.
The collision sensing sensitivity of a car dash cam is the result of the combined effects of hardware performance, software algorithms, installation environment, driving habits, and usage and maintenance. Users should choose products with high-precision G-sensors, intelligent algorithms, and flexible settings based on their actual needs, and install and maintain them properly to fully realize their core value of recording critical evidence and ensuring driving safety.
