Four Wheel Alignment Guide to Understand the Four Wheel Alignment Market

At present, four wheel alignment manufacturers in the market too much, the price is too messy, 30000-180000 have quite a mixed bag, it is people cannot start to buy, here I will wheel alignment knowledge to explain, I hope after reading this article helpful to you.

Four wheel alignments involves knowledge in the field of mechanical, optical, electronic, computer software, mathematical models, and with each other, are indispensable, so a good product must be considerate and nice in all aspects of the job.

The mechanical structure is a four wheel alignment on the basis of a solid long-term will not deform the structure will make the sensor more stable, long-term use without calibration, make the machine more long to serve you. Really high requirements of the manufacturers are using aluminum alloy structure, because the deformation of aluminum after the appropriate approach in the 10-20 years is very small, which is why the aircraft will be extensive use of aluminum sake.

The optical design allows the wheel alignment measurement accuracy can be guaranteed, and be able to avoid the environmental impact of four wheel alignment, a specially designed optical structure can also save the power consumption of the sensor, and sensor battery more durable.

With the development of electronic technology, wheel alignment measurement technique has also undergone tremendous changes:

The first measurement is the most primitive pull tape measure, the guyed measuring devices and measuring four-quadrant photodiode array measurement, and later development to the PSD measurement, CCD measurements, the latter four measurements in accordance with the measurement of light in nature and can be divided into laser and infrared-style. And abroad in recent years developed a new 3D image-based dynamic measurement.

Shortcomings of the original measurements, the accuracy is poor, and the latest 3D measurement in the use of less suitable for the repair industry to use (must be on the absolute level of the lifting platform, before and after to promote in order to measure), here we do not an introduction. Specifically, we introduce the laser PSD, infrared the PSD, laser CCD, infrared CCD four ways.

The laser has many advantages, such as high directivity, monochromaticity, high brightness, and therefore the laser measurement source is difficult to interfere with, the stability is also very good. But for four wheel alignment laser sensor is a semiconductor laser, life is only 5000 hours, theoretical measurement accuracy of less than 0.1 degrees, the actual measurement accuracy is generally difficult to achieve 0.1 degree. Laser on the human eye has a strong harm, for the purpose of protecting the workers, countries have restrictions on the use of such products and regulations. Therefore such products in the phasing out of the list. ?

Infrared with the main job of communication in the four wheel alignment and measurement, the theoretical measurement accuracy can reach 0.01 or even higher, the launch tube at least 10 years under normal conditions of use. However, because any object or light can emit infrared light, and therefore how to remove the mutual interference of outside interference of infrared light and measuring light Infrared wheel locator important and difficult. Fully grasp the technology companies the world only a few.

His English name is PositionSensitiveDetectors PSD, it is a simulation of optoelectronic position sensor, mainly Japanese manufacturers of this device. Analog Devices, and therefore it has some shortcomings, such as temperature stability is not good, not easy to distinguish between light and measuring light interference, linearity than CCD devices. But this is not a solution that can maximize the measurement sampling to compensate for these shortcomings, so as to produce useful products. But most of the measuring range of domestic production PSD products does not exceed plus or minus 6 degrees, the measurement accuracy of only 0.05 to 0.1 degrees plus or minus 20 degrees, only a few measuring range can be achieved an accuracy within 0.05 degrees.

The CCD device is nearly a decade before the light receiving sensor, the output is a digital signal, it has good linearity, temperature stability, through a special filtering algorithm can distinguish between various kinds of interference light, the foreign brands range the light sensors.

However, because the CCD to receive a very wide spectrum - from ultraviolet, visible, infrared can be received, and more sensitive to visible light, hence the CCD as a receiving device of the four wheel alignment design the most difficult. Current mainstream manufacturers more than 2000 lines to 3000 lines of the CCD to produce a wheel alignment measurement range is generally plus or minus 20 degrees or more, in theory, their optical resolution of 0.015 to 0.025 °, while the accuracy is more at about 0.05 degrees.

Number of other photoelectric sensor is a particularly important indicator wheel alignment beam, beam 8 beam "; 2 beam is only the two front wheel sensor to measure only the front wheel toe angle and inclination; six beam There are four sensors, measuring the angle between the front and rear wheels, but do not measure the beam angle of the rear wheel; 8 beam all angles are measured by four sensors. Simply put, beam, beam 8 beam is 2,6,8 a beam angle sensor. Because only 8-beam measurement of the tire all the space angle, these data into the correct formula in order to get an accurate wheel alignment angle values.

A core sensors sensor inclinometer, inclinometer country produced in the world is not much, mainly Germany, Finland, the United States, Japan, South Korea, domestic production is mainly used in aerospace. Germany, the United States, Japan, South Korea, the domestic are basically the same kind of technology - the fluid nature of the production of inclinometer, South Korea's worst (no temperature compensation), Japan (inclinometer earthquake, fell on bad), the United States ( accuracy is not big, tall), China (accuracy is acceptable, tall, expensive), followed by Germany, the better (using the best not inverted); Finland is the application of the latest silicon set circuit good accuracy, good stability, seismic capacity is more suitable for mass production, the technology is more advanced.

The above is from the measurements in terms of the following, we re-transmission Laijiang Jiang:

    Wheel alignment sensor, the sensor and the host will need each other to pass signal and data, the first cable to transmit, and then use infrared light, and then to use HF radio, the latest is the use of Bluetooth communication technology, and perhaps later there other, more advanced communications technology.

The cable is reliable, fast, but inconvenient to use, and transmission line access a limited number of plug plug (500), the line itself is easy to be pulled, pressure, broken, replace the cable cost (import line to a set of more than 3000 yuan).

Infrared light: transmission speed is faster, more convenient to use, long life, but susceptible to occlusion, higher on the environment.

HF radio: Transmission speed is faster, more convenient to use, long life, but susceptible to interference, multiple sets of simultaneous problems (do not have perfect communication protocol do not have the hopping anti-jamming capability, fixed frequency point once interference must be resolved by the manufacturers to come).

Bluetooth: perfect communication protocols, transmission speed, easy to use, long life, stable and reliable communications.

The old wheel alignment measurement speed is very slow, sometimes almost want to wait nearly 30 seconds to update the data once, and even well-known foreign models can only do 2 seconds update time. But in recent years with the development of LSI, the performance of applications in the positioning of four main processing chip (SCM) is increasingly high, which led directly to the wheel alignment measurement speed is also faster and faster, to do good manufacturers have realized the real-time measurement of the four data (all data updates per second more than 2 times), so they would not tune a wrench would have to wait on a little convenient to use.

The computer software will have to be much simpler, as long as it has to lift to adjust toe curve measurement, direct measurement of the steering angle, poor tread wheelbase and front and rear center length difference measurement function is basically complete, of course, have various functions stable, easy to use, fast running speed. As shunting 3D animation, the voice prompts or something in addition to a little help for beginners, there is no other use.

Mathematical model the last and most critical is the measurement of wheel alignment, wheel alignment angle must rely on the calculation formula to get the wheel alignment algorithm, or just approximate algorithm, so that calculated values ​​do not accurate, will repair to cause trouble, ranging from rework, re damages, and a very bad influence to the reputation of the store.

Foreign wheel alignment manufacturers only over 10, while the domestic production of wheel alignment, there are nearly 50, to remove the OEM, can really produce their own will in 20. Them or in cooperation with foreign manufacturers to license production abroad in low-end products, or simply steal other people's technology to its own production, while the real has R & D capabilities, and should be used on the production of not more than five. Some manufacturers do not pay attention to cultivate internal strength, lied to their own products for its own sake, regardless of the actual CCD or Bluetooth, or other advanced technology, this caused confusion in the market of wheel alignment, resulting in the former The complaint rate increased substantially since the period of time. This testing center of the Ministry of Transportation in May of this year, four positioning products on the market thoroughly investigated and tested in accordance with national standards of the wheel alignment, enacted in 2004, 16 censorship, the results of only 4-5 products passed the test. Is one of them, through the testing of products are basically those who really have the company of R & D capabilities, production.