Sensors play a crucial role in electric vehicles (EVs), supporting battery and thermal management, advanced driver-assistance systems (ADAS), and personalized in-cabin experiences. This article reviews the advanced sensor technologies in EVs, explores their essential functions across different vehicle systems, and highlights their impact on efficiency, comfort, and safety.
Battery monitoring and thermal management
Advanced sensors in battery management systems (BMS) continuously monitor the state of charge (SOC) and state of health (SOH), ensuring balanced electrical loads across cells and preventing thermal runaway by regulating voltage and temperature.
Figure 1. An overview of EV sensor placement, showcasing systems for battery and thermal management, electric motor control, and brake and tire monitoring. (Image: Sensata Technologies)
BMS humidity sensors gauge moisture levels, shielding batteries from the hazards of condensation. These sensors also help minimize heat during rapid charging and discharging cycles, reducing battery stress and degradation. In some EV models, specialized fiber Bragg grating (FBG) sensors within the battery assembly monitor resistance changes — which, if unchecked, could cause mechanical strain and structural damage.
Beyond battery management, EV sensors oversee motor inverter temperature to prevent demagnetization and heat-related damage. Specifically, advanced thermocouples or infrared sensors measure temperature gradients across inverter power electronics, maintaining thermal equilibrium and extending the lifespan of EV motors.
Additionally, sensors facilitate temperature regulation in EV HVAC systems across different vehicle loops, such as cabin and power electronics, batteries and onboard chargers, motor and powertrain cooling systems, and external heat exchangers.
The many sensors of ADAS
Sensors embedded in EV ADAS facilitate various automated functions, from adaptive cruise control and lane-keeping assistance to emergency braking, collision avoidance, and full self-driving. LiDAR sensors, for example, play a crucial role in autonomous navigation and safety systems with high-resolution 3D mapping and object detection capabilities.
In contrast to LiDAR, millimeter-wave (MM Wave) radar sensors offer reliable performance in all weather conditions, including rain, snow, and fog. Upgraded sensor technologies, with improved signal processors and more directive antennas, compensate for the radar’s narrower field of view and vulnerability to moisture. These improvements ensure EV ADAS systems function effectively, even when line of sight is compromised.
Figure 2. Illustration of an EV HUD with real-time data projection for navigation, battery status, and driving metrics. (Image: EVEngineeringOnline)
Augmenting the high-definition spatial mapping of LiDAR and the all-weather dependability of radar, sensors in ADAS night vision and conventional cameras collect and process essential visual details for a thorough perception of the environment.
These include:
- Road signals and signs: Identify traffic lights, road signs, and cones to help ADAS comply with traffic laws and adapt to dynamic road conditions.
- Lane demarcations: Ensure EVs stay within their designated lanes.
- Traffic and pedestrians: Scans the surrounding area for pedestrians and vehicles — such as cars, trucks, motorcycles, and bicycles — to detect potential hazards and prevent accidents.
- Parking: Along with ultrasonic (sonar) sensors, provide data for manual and autonomous parking systems and low-speed vehicle maneuvering.
Lastly, inertial measurement units (IMUs) and GPS sensors generate detailed information about vehicle dynamics and precise location. EV ADAS uses this data for automated lane changes, emergency braking, and dynamic route planning. IMUs detect acceleration and rotation with accelerometers and gyroscopes to anticipate vehicle performance and inform control system responses.
Personalized in-cabin experiences and vehicle safety
Many EVs rely on complex sensor networks to deliver personalized, seamless in-cabin experiences. For example, gesture recognition sensors offer drivers and passengers touchless interaction with infotainment systems.
Some EV in-cabin systems use sensors to proactively modify temperature, select audio, customize seat settings, and adjust interior lighting. In-cabin systems also automate windshield wipers and headlight intensity based on driver input and conditions monitored by external sensors.
Many EVs could include heads-up displays (HUDs) to project essential information such as speed, navigation, and alerts directly into the driver’s line of sight. Sensor networks and fusion algorithms will feed real-time data to the HUD, integrating speedometer, GPS, and ADAS outputs.
EV sensors are also part of various in-cabin safety features. Infrared and camera sensors support driver monitoring systems (DMS) that gauge driver alertness, pedal pressure, and steering — activating warnings or taking control when detecting signs of drowsiness or distraction.
“Child left behind” alerts, which are triggered by interior sensors, avert heatstroke in unattended children or pets by reminding drivers to check the rear seats before exiting the vehicle. Occupant classification system (OCS) sensors determine passenger height and weight, ensuring correct seatbelt placement and airbag deployment in the event of a collision.
Notably, sensors support comprehensive EV safety systems that extend well beyond the cabin. Ultrasonic sensors enable blind spot detection (BSD), alerting drivers to vehicles side-approaching or moving in adjacent lanes during lane changes. Additionally, sensors integrated into tire pressure monitoring Systems (TPMS) ensure pressure is maintained at safe levels.
Summary
Advanced sensors are essential in EVs, from battery and thermal management to ADAS and personalized in-cabin experiences. These sensors are embedded throughout EVs, supporting critical functions across different vehicle systems, ensuring efficiency, comfort, and safety for drivers and passengers.
References
- Trends in Sensor Technology and the Electric Vehicle Industry, AZO Sensors
- Sensors Play an Important Role in Battery Management Systems, Assembly Magazine
- Sensing to Solve EV Thermal Challenges, SAE International
- A Review of Sensor Applications in Electric Vehicle Thermal Management Systems, MDPI
- How Self-driving Cars Work: Sensor Systems, Udacity
- Introduction to Autonomous Driving Sensors, Ecotron
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