What are the test methods for the electric wheelchair standards?

What are the test methods for the electric wheelchair standards?

1. Performance test methods

1.1 Maximum speed test
The maximum speed test is one of the key indicators for evaluating the performance of electric wheelchairs. The test method is usually carried out on a flat, dry and windless site to ensure the accuracy of the test results. The electric wheelchair travels at a constant speed with maximum power output, and its speed is measured using a high-precision speed sensor. The average value is taken as the final result after multiple consecutive measurements. According to the international standard ISO 7176-10, the maximum speed of an electric wheelchair should not exceed 6km/h to ensure the safety of the user. In actual tests, some high-performance electric wheelchairs can reach speeds close to this standard. For example, the average maximum speed of a certain brand of electric wheelchair in the test is 5.8km/h, which meets safety regulations and meets the daily travel needs of users.
1.2 Maximum climbing ability test
The maximum climbing ability test is used to evaluate the power performance of electric wheelchairs at different slopes. The test site needs to set up slopes of different slopes, usually ranging from 5° to 15°, to simulate various road conditions in actual use scenarios. The electric wheelchair climbs the slope at a constant speed with maximum power output, and records the maximum slope it can successfully climb. According to the standards of the Rehabilitation Engineering and Assistive Technology Association (RESNA), the maximum climbing ability of an electric wheelchair should be no less than 10°. In actual tests, some electric wheelchairs can reach a climbing ability of 12° or even higher. For example, a certain electric wheelchair can climb stably on a slope with a slope of 12°, showing good power performance and providing convenience for users in complex terrain.
1.3 Endurance test
Endurance is a key factor in measuring the practicality of an electric wheelchair. The test method is to record the distance traveled from the electric wheelchair from full charge to battery exhaustion under standard test conditions, that is, on a flat road, at room temperature and at rated speed. According to the European standard EN 12184, the endurance of an electric wheelchair should be no less than 20km. In actual tests, the endurance of electric wheelchairs of different brands and models varies greatly. A certain high-performance electric wheelchair has a range of 30km in the test, which far exceeds the standard requirements and can meet the needs of users for long-term outdoor activities. In addition, the test should also consider the endurance performance under different usage scenarios. For example, the range will decrease in the case of frequent start-stop or heavy load, which also needs to be detailed in the test report so that users can choose the appropriate electric wheelchair according to their needs.

2. Safety test method

2.1 Stability test
Stability test is an important part to ensure that the electric wheelchair maintains balance and prevents tipping under various road conditions. The test is usually carried out in a venue that simulates the actual usage scenario, including flat roads, slopes, uneven ground, etc. The test method is as follows:
Tilt test: Place the electric wheelchair on a platform with adjustable tilt angle, gradually increase the tilt angle, and record the angle at which the electric wheelchair begins to tilt or tip over. According to the international standard ISO 7176-14, when the electric wheelchair is stationary, the tilt angles forward, backward, left, and right should reach 10°, 10°, 15°, and 15° respectively without tipping over. In the actual test, a certain brand of electric wheelchair can still remain stable when the tilt angle reaches 12°, showing good static stability.
Dynamic stability test: When the electric wheelchair is traveling at the rated speed, observe whether it can maintain stability by suddenly changing the direction of travel or traveling on a slope. For example, when traveling on a slope, the electric wheelchair should be able to smoothly go down the slope without tipping over. According to the ISO 7176-14 standard, when an electric wheelchair is traveling on a slope, its center of gravity should be kept within a reasonable range to ensure dynamic stability. In the actual test, when a certain electric wheelchair was traveling on a 10° slope, the center of gravity was reasonably distributed and no tipping occurred.
Obstacle stability test: Set obstacles of different heights and widths on the driving path of the electric wheelchair, such as small stones, speed bumps, etc., and observe its stability when passing through obstacles. According to the ISO 7176-14 standard, an electric wheelchair should be able to smoothly pass obstacles with a height of no more than 50mm without tipping over. In the actual test, when a certain brand of electric wheelchair passed a speed bump with a height of 40mm, the body was stable and there was no abnormal shaking.

2.2 Braking performance test
The braking performance test is used to evaluate the reaction speed and braking distance of the electric wheelchair during emergency braking to ensure that the user can stop safely in an emergency. The test method is as follows:
Dry braking test: On a dry and flat road, the electric wheelchair is driven at the rated speed, the braking system is suddenly activated, and the distance from the start of braking to complete stop is measured. According to the ISO 7176-13 standard, the braking distance of an electric wheelchair under dry conditions should not exceed 2m. In the actual test, a certain electric wheelchair has a braking distance of 1.8m when driving at a speed of 5km/h under dry conditions, which meets the standard requirements.
Wet braking test: Repeat the above test under conditions simulating a slippery road surface. According to the ISO 7176-13 standard, the braking distance of an electric wheelchair under wet conditions should not exceed 2.5m. In the actual test, a certain brand of electric wheelchair has a braking distance of 2.3m when driving at a speed of 5km/h under wet conditions, showing good wet braking performance.
Slope braking test: Braking tests are performed on slopes of different slopes to record the braking distance and stability of the electric wheelchair at different slopes. According to the ISO 7176-13 standard, when an electric wheelchair brakes on a slope, it should be able to stop smoothly without slipping or tipping over. In the actual test, when a certain electric wheelchair brakes on a 10° slope, the braking distance is 1.5m, and the body is stable without slipping.

2.3 Guard strength test
The guard strength test is used to evaluate the strength and stability of the guards of the electric wheelchair (such as armrests, backrests, footrests, etc.) when they are impacted by external forces to ensure that these devices will not be damaged or deformed during use. The test method is as follows:
Armrest strength test: Use standard tensile testing equipment to apply gradually increasing tensile forces to the armrests and record the deformation of the armrests under different tensile forces. According to the ISO 7176-11 standard, the armrests should be able to withstand a tensile force of at least 150N without permanent deformation. In actual tests, the armrests of a certain brand of electric wheelchairs only showed slight elastic deformation when subjected to a 200N tensile force, and no permanent deformation occurred, showing good strength.
Backrest strength test: Apply gradually increasing pressure to the backrest, and record the deformation of the backrest under different pressures. According to the ISO 7176-11 standard, the backrest should be able to withstand at least 200N of pressure without permanent deformation. In actual tests, the backrest of a certain electric wheelchair only showed slight elastic deformation when subjected to a 250N pressure, and no permanent deformation occurred, meeting the standard requirements.
Pedal strength test: Apply gradually increasing pressure to the pedal, and record the deformation of the pedal under different pressures. According to the ISO 7176-11 standard, the pedal should be able to withstand at least 100N of pressure without permanent deformation. In actual tests, the pedal of a certain brand of electric wheelchair only showed slight elastic deformation when subjected to a 120N pressure, and no permanent deformation occurred, showing good strength.

3. Comfort test method

3.1 Seat comfort test
Seat comfort is an important part of the user experience of electric wheelchairs. Good seat design can significantly improve the user’s comfort and satisfaction. The test method is as follows:
Pressure distribution test: Use a pressure distribution sensor pad placed on the seat to simulate the user’s sitting posture and measure the pressure distribution on the seat surface. According to the principle of ergonomics, the ideal seat pressure distribution should be uniform to avoid excessive local pressure causing discomfort to the user. In actual tests, the seat of a certain brand of electric wheelchair showed in the pressure distribution test that the pressure was mainly concentrated in the ischial area, but by optimizing the seat filling material and shape design, the pressure distribution was significantly improved, and the user did not experience obvious discomfort after riding for a long time.
Seat material test: Evaluate the breathability, moisture absorption and durability of the seat material. The breathability test is completed by measuring the air permeability of the seat material. Good breathability can reduce the stuffiness of the user when riding for a long time. The hygroscopicity test measures the moisture absorption capacity of the seat material to ensure that the user can remain comfortable in a humid environment. The durability test simulates long-term use scenarios and repeatedly rubs and stretches the seat material to evaluate its wear resistance and deformation resistance. In the actual test, the seat of a certain electric wheelchair uses a material with high air permeability and good moisture absorption, with an air permeability of up to 80% and a moisture absorption rate of more than 30%. After 1,000 friction and stretch tests, the material did not show obvious wear or deformation, showing good comprehensive performance.
Seat adjustment function test: Evaluate the adjustment function of the seat, including the adjustment range of seat height, angle and depth. According to the ISO 7176-15 standard, the seat of an electric wheelchair should have a sufficient adjustment range to adapt to the body size and comfort needs of different users. In the actual test, the seat height adjustment range of a certain brand of electric wheelchair is 300mm to 500mm, the seat angle adjustment range is 0° to 45°, and the seat depth adjustment range is 350mm to 450mm, which can meet the adjustment needs of most users and provide users with a personalized comfort experience.

3.2 Vibration and noise test
The vibration and noise levels directly affect the comfort of the electric wheelchair. Excessive vibration and noise will reduce the user’s comfort and satisfaction. The test method is as follows:
Vibration test: Use vibration sensors installed on key parts of the electric wheelchair, such as the seat, armrests and wheels, to measure the vibration acceleration of the electric wheelchair at different driving speeds and road conditions. According to the ISO 7176-16 standard, when the electric wheelchair is driving at the rated speed on a flat road, the vibration acceleration at the seat should not exceed 0.5g. In the actual test, when a certain electric wheelchair was driving at a speed of 5km/h on a flat road, the vibration acceleration at the seat was 0.3g, which met the standard requirements. When driving on uneven roads, the vibration acceleration increased, but by optimizing the suspension system and wheel design, the vibration acceleration was controlled within 0.7g, ensuring that the user can maintain a relatively comfortable riding experience under complex road conditions.
Noise test: Use a decibel meter to measure the noise level of the electric wheelchair at different locations around it under different operating conditions. According to ISO 7176-16, the noise level of an electric wheelchair should not exceed 60 decibels when it is traveling at rated speed on a flat road. In actual testing, the noise level of a certain brand of electric wheelchair was 55 decibels when it was traveling at a speed of 5km/h on a flat road, which meets the standard requirements. The noise level increases when climbing a slope or accelerating, but by optimizing the design of the motor and transmission system, the noise level is controlled within 65 decibels, providing users with a relatively quiet use environment.

4. Reliability test method

4.1 Durability test
Durability test is an important part of evaluating the long-term performance of electric wheelchairs, which aims to ensure that the product can maintain good functions and performance after long-term use. The test method is as follows:
Driving mileage durability test: Under standard test conditions, simulate the actual use scenarios of electric wheelchairs, including flat roads, ramps, uneven ground, etc., and record the performance changes of electric wheelchairs after a certain mileage of continuous driving. According to industry standards, electric wheelchairs should be able to complete at least 1000km of durability test without major failures. In actual tests, after a certain electric wheelchair completed a 1200km durability test, all performance indicators remained within the normal range, showing good durability.
Frequent start-stop durability test: simulate the use of electric wheelchairs in frequent start-stop scenarios, such as use on urban streets or indoor environments. Within a certain period of time, repeatedly start and stop the electric wheelchair, and record its performance changes after frequent start-stop. According to the test requirements, the electric wheelchair should be able to withstand at least 1000 frequent start-stop tests, and the motor and control system should have no obvious faults. In actual tests, after 1500 frequent start-stop tests, the motor performance of a certain brand of electric wheelchair was stable, the control system responded normally, and it met the durability requirements.
Load durability test: Loads of different weights are applied to the electric wheelchair to simulate the use scenarios of users with different weights, and the performance changes of the electric wheelchair after long-term load operation are recorded. According to the standard, the electric wheelchair should be able to carry the maximum design load (such as 120kg) and run continuously for a certain period of time (such as 8 hours) without failure. In actual tests, after a certain electric wheelchair carried a load of 120kg and ran continuously for 10 hours, the frame structure did not deform, and the motor ran normally, showing good load durability.

4.2 Component reliability test
Component reliability test is used to evaluate the performance and stability of each key component of the electric wheelchair in long-term use, and ensure that the components can work normally under various working conditions. The test method is as follows:
Motor reliability test: The motor of the electric wheelchair is tested separately, including continuous operation test, overload test and high temperature test. In the continuous operation test, the motor should be able to run continuously for at least 100 hours without failure. In the overload test, the motor should be able to withstand a short overload (such as 1.5 times the rated power) without damage. In the high temperature test, the motor should be able to work normally and have no obvious performance degradation after running in a high temperature environment (such as 50°C) for a certain period of time. In the actual test, the motor of a certain brand of electric wheelchair has stable performance after running continuously for 120 hours; the motor is not damaged after running for 10 minutes at 1.5 times the overload; the motor runs normally after running for 2 hours in a high temperature environment of 50°C, showing good reliability.
Battery reliability test: The battery of the electric wheelchair is subjected to charge and discharge cycle test, high temperature test and low temperature test, etc. In the charge and discharge cycle test, the battery should be able to complete at least 500 charge and discharge cycles, and the capacity retention rate should not be less than 80%. In the high temperature test, the battery should have no abnormal phenomena such as leakage and bulging after being stored in a high temperature environment (such as 50°C) for a certain period of time. In the low temperature test, the battery should be able to discharge normally in a low temperature environment (such as -20°C), and the discharge capacity should not be less than 70% of the rated capacity. In actual tests, the battery of a certain electric wheelchair has a capacity retention rate of 85% after completing 600 charge and discharge cycles; after being stored in a high temperature environment of 50℃ for 24 hours, the battery has no leakage or bulging phenomenon; when discharged in a low temperature environment of -20℃, the discharge capacity is 75% of the rated capacity, which meets the reliability requirements.
Wheel reliability test: The wheels of the electric wheelchair are subjected to rolling endurance test, impact test and wear resistance test. In the rolling endurance test, the wheel should be able to roll continuously for a certain mileage (such as 500km) without damage. In the impact test, the wheel should be able to withstand a vertical impact of a certain height (such as 100mm) without deformation. In the wear resistance test, the degree of wear of the wheel should be within the allowable range after a certain mileage (such as 1000km). In actual tests, the wheels of a certain brand of electric wheelchair have no obvious damage after rolling continuously for 600km; in the vertical impact test at a height of 100mm, the wheel has no deformation; after the 1000km wear resistance test, the degree of wear of the wheel meets the standard requirements, showing good reliability.
Reliability test of electronic control system: The electronic control system of the electric wheelchair is subjected to anti-interference test, high temperature test and low temperature test, etc. In the anti-interference test, the electronic control system should be able to work normally under a certain intensity of electromagnetic interference without misoperation or freezing. In the high temperature test, the electronic control system should be able to work normally and have no obvious performance degradation after running for a certain period of time in a high temperature environment (such as 50°C). In the low temperature test, the electronic control system should be able to start and run normally in a low temperature environment (such as -20°C). In the actual test, the electronic control system of a certain electric wheelchair operated normally under electromagnetic interference with an anti-interference intensity of 10V/m; after running for 2 hours in a high temperature environment of 50°C, the performance was stable; it started and ran normally in a low temperature environment of -20°C, showing good reliability.

5. Electromagnetic compatibility test method

5.1 Electromagnetic interference test
Electromagnetic interference test is an important part of evaluating whether the electric wheelchair will interfere with other electronic equipment during operation. The test is usually carried out in an electromagnetic shielding room to eliminate interference from the external electromagnetic environment and ensure the accuracy of the test results.
Radiated interference test: Place the electric wheelchair in the center of the test site, turn on the electric wheelchair and put it in normal operation, and use a spectrum analyzer to measure its radiated interference level in different frequency bands (such as 30MHz – 1GHz) at different distances (such as 1m, 3m, 10m). According to the international standard IEC 60601-1-2, the radiated interference level of the electric wheelchair should be lower than the specified limit to avoid interference with nearby medical equipment, communication equipment, etc. In the actual test, the radiated interference level of a certain brand of electric wheelchair at 1m was 30dBμV/m, which is much lower than the standard limit, showing good radiated interference control ability.
Conducted interference test: Connect the power cord of the electric wheelchair to the conducted interference test equipment, turn on the electric wheelchair and put it in normal operation, and measure the conducted interference voltage in different frequency bands on the power cord. According to the IEC 60601-1-2 standard, the conducted interference voltage of the electric wheelchair should not exceed the specified limit to prevent interference with other equipment in the power grid. In actual tests, the conducted interference voltage of a certain electric wheelchair is 20mV in the 50MHz frequency band, which meets the standard requirements, indicating that its conducted interference is well controlled.

5.2 Electromagnetic immunity test
The electromagnetic immunity test is used to evaluate the normal operation ability of electric wheelchairs when subjected to external electromagnetic interference, ensuring that users can use electric wheelchairs safely and stably in complex electromagnetic environments.
Radio frequency electromagnetic field radiation immunity test: Place the electric wheelchair in an electromagnetic shielding room, and use an RF signal generator to radiate interference to the electric wheelchair at different frequency bands (such as 80MHz – 2.5GHz) and different field strengths (such as 10V/m, 30V/m) to observe whether the function of the electric wheelchair is affected. According to the IEC 60601-1-2 standard, electric wheelchairs should be able to operate normally under the specified field strength without loss of function or performance degradation. In actual tests, a certain brand of electric wheelchairs has normal functions under a field strength of 30V/m, and there are no abnormalities in driving speed, steering control, etc., showing good radio frequency electromagnetic field radiation immunity.
Electrical fast transient pulse group immunity test: Use an electrical fast transient pulse group generator to apply a transient pulse group of a certain amplitude (such as 2kV) and a certain frequency (such as 5kHz) to the power line and signal line of the electric wheelchair, and observe the operation of the electric wheelchair under interference. According to the IEC 60601-1-2 standard, the electric wheelchair should be able to withstand the specified transient pulse group interference without misoperation or loss of function. In the actual test, under the 2kV transient pulse group interference, the motor of a certain electric wheelchair runs smoothly, the control system responds normally, and there is no deadlock or misoperation, which meets the standard requirements.
Surge immunity test: Use a surge generator to apply a surge voltage of a certain amplitude (such as 1kV) to the power line of the electric wheelchair to simulate the lightning surge or switch operation surge in the power grid, and observe the operation of the electric wheelchair under the surge impact. According to the IEC 60601-1-2 standard, the electric wheelchair should be able to withstand the specified surge voltage without damage or abnormal function. In the actual test, a certain brand of electric wheelchair did not show any abnormality under the impact of 1kV surge voltage, showing good surge immunity performance.

6. Environmental adaptability test method

6.1 High and low temperature test
High and low temperature test is an important part of evaluating the performance of electric wheelchairs under extreme temperature conditions to ensure that they can be used normally in different climate environments.
High temperature test: Place the electric wheelchair in a high temperature environment box, set the temperature to 40℃ to 50℃, run it for a certain period of time (such as 2 hours), and observe its performance changes. According to the international standard ISO 7176-20, electric wheelchairs should be able to start, drive and brake normally in high temperature environments, and the motor and battery temperatures should be kept within a safe range. In the actual test, after a certain brand of electric wheelchair ran for 2 hours in a 45℃ environment, the motor temperature was 60℃ and the battery temperature was 45℃, both within the safe range, and all functions were normal.
Low temperature test: Place the electric wheelchair in a low temperature environment box, set the temperature to -10℃ to -20℃, run it for a certain period of time (such as 2 hours), and observe its performance changes. According to ISO 7176-20, electric wheelchairs should be able to start, drive and brake normally in low temperature environments, and the battery should be able to discharge normally. In actual tests, after a certain electric wheelchair ran for 2 hours in a -15℃ environment, the battery discharge capacity was 80% of the rated capacity, and the motor ran normally, showing good low temperature adaptability.

6.2 Humidity test
The humidity test is used to evaluate the performance and reliability of electric wheelchairs in high humidity environments to ensure that they will not fail in humid environments.
High humidity test: Place the electric wheelchair in a high humidity environment box, set the relative humidity to 90% to 95%, run it continuously for a certain period of time (such as 24 hours), and observe its performance changes. According to ISO 7176-20, electric wheelchairs should be able to start, drive and brake normally in a high humidity environment, and the electronic control system should have no short circuit or fault phenomenon. In actual tests, after a certain brand of electric wheelchair ran for 24 hours in a 95% relative humidity environment, the electronic control system ran normally without short circuit or fault, showing good moisture resistance.
Wet and hot cycle test: simulate the use of electric wheelchairs in a repeatedly changing wet and hot environment, and cycle the electric wheelchair between high temperature and high humidity (such as 40℃, 90% relative humidity) and normal temperature and humidity (such as 25℃, 50% relative humidity). Each cycle lasts for 24 hours. Perform multiple cycles (such as 10 cycles) to observe its performance changes. According to ISO 7176-20 standard, electric wheelchairs should have no obvious performance degradation or failure after wet and hot cycle test. In actual tests, after completing 10 wet and hot cycle tests, all performance indicators of a certain electric wheelchair remained within the normal range, showing good wet and hot adaptability.

7. Other test methods

7.1 Charging performance test
The charging performance test is a key link in evaluating the convenience and efficiency of electric wheelchairs, mainly covering charging time, charging efficiency and charging safety.
Charging time test: When the electric wheelchair is exhausted, use a standard charger to charge it, and record the time required from the start of charging to the full battery. According to industry practice, the charging time of electric wheelchairs should be controlled within a reasonable range to meet the daily needs of users. In actual tests, it only takes 4 hours for a certain electric wheelchair to charge from 0% to 100%, which is much shorter than the charging time of more than 8 hours for some products, significantly improving the user experience.
Charging efficiency test: The charging efficiency is calculated by measuring the input power during the charging process and the actual power charged into the battery. An efficient charging system can not only shorten the charging time, but also reduce energy waste. In the charging efficiency test of a certain brand of electric wheelchair, the ratio of input power to actual charged power reached 90%, indicating that its charging system has less loss during energy conversion and higher charging efficiency.
Charging safety test: Simulate various abnormal charging conditions, such as overcharging, short circuit, high temperature charging, etc., to evaluate the charging safety performance of electric wheelchairs. According to the UL 2272 standard, the charging system of electric wheelchairs should have functions such as overcharge protection, short circuit protection and temperature protection to prevent battery damage or safety accidents. In actual tests, when a certain electric wheelchair is overcharged, the charger can automatically cut off the power supply; in the short circuit test, the charger quickly enters the protection state, and no dangerous conditions such as fire or explosion occur, showing good charging safety.

7.2 Maneuverability Test
The maneuverability test is designed to evaluate the driving convenience and flexibility of the electric wheelchair, ensuring that the user can easily and safely control the wheelchair.
Steering flexibility test: In the specified test site, set up circular tracks of different radii, let the electric wheelchair travel at the rated speed and complete the turn, and measure its minimum turning radius. A smaller turning radius means that the electric wheelchair has better flexibility in a narrow space. According to the ISO 7176-1 standard, the minimum turning radius of an electric wheelchair should not exceed 1.5 meters. In actual tests, the minimum turning radius of a certain brand of electric wheelchair is only 1.2 meters, which enables it to turn easily in indoor environments or crowded streets, making it convenient for users to control.
Maneuverability stability test: During the driving of the electric wheelchair, observe its maneuverability stability by changing the driving speed, direction and load. The tester needs to record whether the electric wheelchair has unstable phenomena such as shaking, deviation from the predetermined trajectory, etc. under different working conditions. When a certain electric wheelchair is loaded with 120kg, driving at a speed of 5km/h and making a sharp turn, the body is stable, without obvious shaking or deviation from the trajectory, showing good maneuverability stability.
Ease of operation test: evaluate whether the control interface design of the electric wheelchair is user-friendly and easy to operate. By inviting users of different ages and physical conditions to perform actual operations, their feedback on the ease of operation is collected. A certain brand of electric wheelchair uses an intuitive control handle with functions such as one-button start, speed adjustment and direction control. Users can operate it proficiently without complex training, and its ease of operation has been unanimously praised by users.