Noise testing of electric scooters for the elderly: ensuring quiet travel

Noise testing of electric scooters for the elderly: ensuring quiet travel
In today’s electric scooter market for the elderly, the noise level of the vehicle has become one of the key factors in measuring its quality and user experience. For international wholesale buyers, it is crucial to have a deep understanding of the noise testing of electric scooters for the elderly, because this is not only related to the market competitiveness of the product, but also directly related to the user satisfaction and safety of elderly users. This article will explore in depth all aspects of noise testing of electric scooters for the elderly, including the importance of testing, testing standards, testing methods, and how to optimize based on test results.

I. The importance of noise testing
(I) Improving driving comfort
The main user group of electric scooters for the elderly is the elderly, who have high requirements for vehicle comfort. A lower noise level can create a quiet and comfortable driving environment for the elderly, allowing them to relax and enjoy the fun of traveling during driving, and reduce fatigue and discomfort caused by noise.
(II) Ensure driving safety
Excessive noise may interfere with the elderly’s perception of ambient sounds, such as horns, brakes, pedestrian warnings, etc., thereby affecting their driving safety. Through effective noise testing and control, it can be ensured that the noise of electric scooters for the elderly is within a reasonable range during driving, helping the elderly to better perceive the surrounding environment, respond in time, and reduce the risk of accidents.
(III) Meeting market demand and regulatory requirements
As people’s pursuit of quality of life continues to improve, the market demand for low-noise electric scooters for the elderly is growing. At the same time, many countries and regions have also formulated relevant noise emission regulations and standards to reduce the noise pollution of vehicles to the environment. Conducting noise testing helps manufacturers of electric scooters for the elderly to ensure that their products meet these regulatory requirements, avoid product recalls or market bans due to noise problems, and thus enhance the market competitiveness of their products.

II. Noise testing standards
(I) International standards
ISO 362: This is a general method standard widely used internationally to measure the external noise of road vehicles. It specifies the methods and requirements for measuring the passing noise of vehicles under different driving conditions, such as acceleration and constant speed driving. The standard has detailed provisions on measurement sites, equipment, vehicle operating status, and data processing, ensuring the accuracy and comparability of test results. Many countries and regions refer to ISO 362 when formulating their own vehicle noise regulations.
ISO 11866: This standard applies to light electric vehicles, including electric scooters for the elderly. It regulates the noise measurement methods, measurement locations, environmental conditions, etc. of electric vehicles. For example, when measuring the noise inside the vehicle, it stipulates that the measurement points should be placed near the ears of the driver and passengers, as well as the stability and repeatability requirements for measuring noise at different vehicle speeds.
(II) Domestic standards
GB/T 18697: This standard specifies the noise measurement method for electric powertrains for electric vehicles. It provides detailed guidance on the noise measurement of electric powertrains for elderly electric scooters under different operating conditions, such as sound pressure level and sound power level measurement at different speeds and torques. The standard also clarifies the accuracy of the measuring equipment, the calibration method, and the requirements for the test environment, ensuring the reliability of the measurement results, and providing an important basis for manufacturers of electric scooters for the elderly in controlling powertrain noise.
GB/T 37153: Mainly regulates the electromagnetic compatibility (EMC) and noise limits of electric vehicles. Although its focus is on electromagnetic compatibility, it also involves relevant requirements for noise, which has a certain reference value for the overall noise control and testing of electric scooters for the elderly.

III. Noise test method
(I) In-vehicle noise test
Measurement point arrangement: Usually, measurement points are arranged near the ears of the driver and passengers in the car to accurately measure the noise actually received by the human ear. In addition, measurement points are also arranged in other locations inside the vehicle, such as near the instrument panel and inside the door, to comprehensively evaluate the noise distribution at different locations in the vehicle.
Test conditions: Includes starting and idling conditions when the vehicle is stationary, as well as driving conditions at different speeds, such as low-speed driving (0-20km/h), medium-speed driving (20-40km/h) and high-speed driving (40km/h or more, depending on the maximum speed of the vehicle). Under each condition, the steady-state noise and transient noise inside the vehicle are measured separately, such as noise changes during acceleration and deceleration.
Measurement equipment: Generally, a precision sound level meter or noise analyzer is used, equipped with a 1/1 or 1/3 octave filter to measure the noise level in different frequency ranges. At the same time, in order to ensure the accuracy of the measurement results, the measurement equipment needs to be calibrated regularly using a calibrator.
(II) External noise test
Measurement point arrangement: External noise measurement points are usually arranged at a certain distance on both sides and behind the vehicle, such as one measurement point at the front and rear wheel arches on the side of the vehicle, and one measurement point at 1.5m from the center line of the vehicle behind the vehicle. The locations of these measurement points are determined according to relevant noise test standards and can represent the noise impact of the vehicle on the surrounding environment during driving.
Test conditions: Mainly simulate different working conditions of the vehicle during actual driving, including the process of accelerating the vehicle from a standstill to a certain speed, and the stable state when driving at different speeds. During the test, the maximum noise level and equivalent continuous noise level generated by the vehicle under different working conditions are measured.
Measuring equipment: In addition to the sound level meter and noise analyzer, the vehicle exterior noise test also requires the use of some auxiliary equipment, such as anemometers, to monitor the ambient wind speed and direction during the test, because wind speed and wind direction have an impact on the propagation of noise. At the same time, in order to ensure the comparability of the measurement results, the test is usually carried out on a dedicated test track or a flat open field that meets the standard requirements.
(III) Power system noise test
Measurement point layout: For the electric power system of the elderly electric scooter, the measurement points are arranged around key components such as the motor, controller, and reducer. The location of these measurement points should be able to accurately reflect the noise radiation of each component of the power system during operation, and at the same time, it is also necessary to consider avoiding interference from other noise sources.
Test conditions: Since the noise characteristics of the electric power system are closely related to the operating state of the vehicle, it is necessary to test under different power system operating modes, such as different vehicle speeds and different load conditions in pure electric mode, and engine start-up and switching conditions in hybrid mode. By measuring the noise of the power system under different working conditions, we can gain a deep understanding of the mechanism and change law of its noise generation.
Measuring equipment: In addition to conventional noise measuring equipment, some special equipment is also needed to measure parameters such as vibration and speed of the power system, because vibration is one of the important factors causing noise, and speed directly affects the noise frequency characteristics of the electric power system. For example, vibration sensors are used to measure the vibration acceleration of the motor and reducer, and speed sensors are used to measure the speed of the motor, etc. Then, the vibration and speed data are correlated with the noise data through data analysis software.
(IV) Road noise test
Measurement point layout: Road noise measurement points are generally arranged in front and behind the direction of vehicle travel, at a certain height from the road surface, to measure the impact of the noise generated by the contact between the tire and the road surface when the vehicle is driving on the external environment. At the same time, in order to analyze the impact of road surface type on noise, measurement points will also be arranged on different road surface types, such as asphalt road surface, cement road surface, masonry road surface, etc.
Test conditions: The measurement is mainly carried out when the vehicle is driving at different speeds, focusing on the road noise of the vehicle within the common driving speed range. In addition, some special working conditions will be tested, such as the noise changes when the vehicle passes through uneven roads such as speed bumps and potholes, in order to evaluate the adaptability of the vehicle to different road conditions and its noise control ability.
Measuring equipment: In addition to sound level meters and noise analyzers, road noise testing also requires the use of special road noise measuring equipment, such as tire noise sensors. These sensors can more accurately capture the noise signals generated by the contact between the tire and the road surface, and analyze them through data processing software to determine the main sources and frequency characteristics of road noise.

IV. Factors affecting the noise of electric scooters for the elderly and optimization measures
(I) Motor noise
Influencing factors: The electromagnetic noise of the motor is caused by the imbalance of the air gap magnetic field between the motor stator and rotor, and its frequency is related to the speed and number of poles of the motor. The mechanical noise of the motor mainly comes from the imbalance of the motor rotor, bearing wear and other factors, which will cause the motor to vibrate during rotation, thereby causing noise.
Optimization measures: Use high-precision motor manufacturing technology to improve the concentricity of the motor stator and rotor and reduce the imbalance of the air gap magnetic field. At the same time, high-quality bearings are selected and strict dynamic balancing tests are carried out to reduce the vibration and mechanical noise of the motor. In addition, optimizing the winding design and control strategy of the motor can effectively reduce the electromagnetic noise of the motor. For example, the use of advanced vector control technology and harmonic suppression technology can make the motor run more smoothly and reduce the generation of electromagnetic noise.
(II) Tire noise
Influencing factors: Factors such as tire pattern design, material, and contact characteristics with the road surface will affect tire noise. Different pattern shapes and arrangements will affect the air fluctuations and friction characteristics when the tire contacts the road surface, thereby generating noises of different frequencies and intensities. The hardness and elasticity of the tire material will also affect the vibration and noise generated when it contacts the road surface.
Optimization measures: Choose low-noise tires suitable for elderly electric scooters. The pattern design should try to avoid overly complex shapes and deep grooves to reduce the noise generated by air fluctuations. At the same time, the material of the tire should have appropriate elasticity and damping characteristics, which can effectively absorb and slow down vibrations and reduce noise. In addition, regularly checking and maintaining the tire pressure to ensure good contact between the tire and the road surface can also reduce tire noise to a certain extent. Manufacturers can also cooperate with tire manufacturers to jointly develop special low-noise tires for electric scooters for the elderly.
(III) Body structure noise
Influencing factors: Insufficient rigidity and strength of the body structure will cause the vehicle to vibrate and deform easily during driving, which will cause mutual collision and friction between the various parts of the body, generating noise. In addition, the sound insulation material and sealing performance of the body will also affect the noise level inside the car. If the body sound insulation material is insufficient or the sealing performance is poor, external noise is easily transmitted into the car, and some noise inside the car will also be transmitted to the outside of the car.
Optimization measures: Strengthen the design and optimization of the body structure, improve the rigidity and strength of the body, and reduce body vibration. Add reinforcement ribs and support structures to key parts of the body, and use high-strength steel or lightweight materials to improve the overall performance of the body. At the same time, use high-quality sound insulation materials, such as sound insulation felt, sound insulation foam, etc., to soundproof the body, especially in doors, windows, floors and other parts, to enhance the sound insulation effect inside the car. In addition, improve the sealing performance of the body, check and repair the gaps between the various parts of the body, and prevent the intrusion of external noise and the leakage of internal noise.
(IV) Transmission system noise
Influencing factors: The gear meshing accuracy, bearing quality and lubrication condition of the transmission system will affect the noise during its operation. Low gear accuracy will cause impact and vibration during meshing, which will cause gear noise. Poor bearing quality and lubrication condition will also cause bearing wear and vibration, increasing the noise of the transmission system.
Optimization measures: Use high-precision gear manufacturing technology to improve the meshing accuracy and surface quality of the gears and reduce the impact and vibration of the gears during meshing. Select high-quality bearings and regularly check and maintain the lubrication condition of the bearings to ensure the good operation of the bearings. Adding shock-absorbing and noise-reducing devices such as shock-absorbing pads and soundproof covers to the transmission system can further reduce the noise transmission of the transmission system. At the same time, optimizing the design and layout of the transmission system, reducing the distance between gears and bearings, and improving the overall stiffness of the transmission system will also help reduce noise.

V. Case analysis
[Brand name] Elderly electric scooters attach great importance to noise testing and control during the development of their new products. By adopting advanced motor technology and optimized body structure design, the noise level of the vehicle has been successfully reduced. In the in-car noise test, the in-car noise of this scooter at different speeds is lower than that of products of the same level, providing a more comfortable driving environment for the elderly. At the same time, in the external noise test, its noise emissions also meet strict international and domestic standards, showing good environmental performance. This successful case fully proves that through scientific noise testing and effective optimization measures, the product quality and market competitiveness of electric scooters for the elderly can be significantly improved.

VI. Future Development Trends and Summary
With the continuous advancement of technology and the improvement of people’s requirements for quality of life, the noise testing and control of electric scooters for the elderly will develop in a more refined and intelligent direction. Future noise testing methods will be more accurate and efficient, and can more comprehensively evaluate the noise performance of vehicles under various actual driving conditions. At the same time, with the help of advanced computer simulation technology and acoustic analysis software, noise problems can be more effectively predicted and optimized in the product design stage, reducing R&D costs and production risks.
For international wholesale buyers, when choosing electric scooters for the elderly, they should pay full attention to the noise test results and related performance indicators of the products. This will help them provide good products for elderly users, meet market demand, and also comply with the development trend of environmental protection and safety. In short, noise testing, as an important part of quality control and product optimization of electric scooters for the elderly, will play an increasingly important role in promoting the healthy development of the industry and improving the quality of life of the elderly.