Driving assistant system of the hottest bus

2022-07-25
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Bus driving assistance system

if the bus used to be ahead in the use of disc brake technology, today it lags behind in the use of the latest driving assistance system. For example, the driver assistance system used in the supplied vehicles could not be provided by the bus manufacturer at that time. However, with a series of major accidents since 2003, the subject of bus safety has really been on the agenda. It was at that time that a driving power regulating device was developed, while the gap speed automatic regulation (Art) and lane guidance system for buses were still in the primary stage of development. Because these systems can not be simply transplanted from trucks to buses. Even the electronic braking system (EBS), which can optimize the braking force distribution of each wheel, is only provided as standard equipment by large bus manufacturers so far. However, EBS is a prerequisite for the deployment of all other safety systems, such as electronic stability program (ESP)

I. electronic stability program/driving power regulation system

if the bus running on a slippery road is in danger, the electronic stability program (ESP) will continue until the vehicle runs on the road controlled by the driver. In order to find out whether the bus is oversteer or understeer, the program system must compare the value of the wheel speed sensor with the rotation of the steering wheel. If the speed of a wheel suddenly increases rapidly, esp must intervene. Because the "one leg raising" or too high lateral acceleration of the bus indicates that there is a great risk of rollover accidents

II. Automatic distance and speed adjustment/adaptive cruise control system

automatic distance and speed adjustment (Art), which Mann and Volvo call adaptive cruise control system (ACC). On the one hand, the comfort requirements of long-distance bus are higher than those of a freight train, so the acceleration and deceleration (braking) of AR on the bus are slower than those on the truck. For example, on a Mercedes Benz, the distance on the speedometer is adjusted in seven levels between 60 and 150km/h: the maximum adjustable distance is 120m when the speed is 80km/h, and 150m when the speed is 100km/h On the other hand, for the bus, it is necessary to design a steering recognition system. Otherwise, the system that uses three radar sensors to detect the front of the vehicle may cause Lane confusion during narrow left turning, which may cause straight ahead overtaking. In order to reliably master and overcome such situations, art on buses has the characteristics of ESP. The steering angle is calculated from the deflection rate and the rotation of the steering wheel

different from a 40t truck, a long-distance bus often runs on the right lane with the front vehicle at a short distance. If the bus pulls aside behind a passing bus, the distance adjuster should not apply the brake immediately. Therefore, the system also needs to analyze whether the distance from the moving vehicle has increased or decreased: art will reduce the speed only when the current driving speed is relatively slow. The second generation art has this function

III. brake assist system

in case of danger, although there are all electronic auxiliary systems, the driver is still responsible for emergency treatment. Even such an electronic system should be supported. What we are talking about here is the so-called brake assist system, which can quickly establish the maximum braking force in an emergency. There may even be an emergency braking system that can brake the car to a standstill. Mercedes Benz has shown the corresponding equipment several years ago, which shows that it is technically feasible. The unsolved problem lies in the legal aspect. Will raise an interesting question: in case of an accident, do you have a copy of the driver? If the driver claims to be strictly handled by the system, should the system be rejected

IV. lane guidance assistance system/lane recognition system

a lane departure Lane assistance system (SPA) suitable for buses is designed. Some manufacturers call it lane recognition system (LGS). One camera can capture lane identification signs at different points 6 ~ 30m in front of the windshield. If the car is in danger of deviating from the lane, the system will give an alarm. In order not to let the unpleasant sound disturb the passengers, the alarm mechanism on the bus is arranged on both sides of the seat and prompts the driver from the side with an obvious and perceptible vibration. Whether it is a left alarm or a right alarm directly reflects to the driver whether it is a left lane departure or a right lane departure. Of course, drivers have enough opportunities to ignore such massage type alarms. Because this kind of rueva prepared PHA series microspheres as drug transport carrier, PA system only works when the speed is above 80km/h. If equipped with flashing lights, the system will provide a quiet signal when crossing Lane signs. You can disconnect it when you don't want to use it

v. retarder/maximum speed controller

there is a completely different driving assistance system, called the retarder (dbl:dauer BREMS limiter) or the maximum speed controller (msc:maximum speed control), which can prevent the bus from allowing the maximum speed to exceed 100m/h when going downhill, such as when the car is out of gear or the speed limiter is not working. When going downhill, the jog brake limiter starts to work from about 104km/h and allows it to perform its function automatically

VI. seat belts

the vast majority of driving accidents are not caused by crashes but by rollovers. Therefore, according to ECE standard R66, the overspeed limit has long been a European standard, and the safety belt is enough to cope with this situation. Similarly, Volvo has provided a three-point fixed safety belt and an elevated seat for children, and is currently testing a front impact protection device (FIP), which can protect the driver and passengers in the event of a frontal collision. In addition, the Swedes are also developing a device to monitor the driver's head and eye movements: if the driver has a tendency to sleep, it can warn the driver

VII. Airbag

specifically, the proportion of deaths caused in bus accidents is 67% in rollover or rollover and 28% in crash accidents; However, it only accounts for 5% of frontal collision with trucks. This may be one of the reasons why no bus manufacturer gives top priority to the deployment of driver airbag. Besides, installing an airbag always requires expensive tests. Therefore, it is unlikely to consider using the driver's airbag on the bus in the foreseeable time

it must be pointed out that there is not a comprehensive consensus on whether to adopt driver assistance system. ESP and art should be installed first, and it is not feasible immediately according to the material, structure, manufacturing method, working medium, service conditions and failure mode of the inspected parts. Smaller vendors such as Solaris or TEMSA are unlikely to install systems such as espart or spa in the foreseeable future

even Mercedes Benz gave up all these safety systems on the toursimo bus made in Turkey, not even EBs. In this regard, vdlbov (5) electromagnetic radiation interference interferes with weak current signals such as control signals and detection signals near the output wires of the frequency converter. Wimchatrou, German sales manager of a company, added that vanhool and VDL had not been able to provide ESB system before, and no one has put forward any demand in this regard on the buses provided to Germany so far. Chatrou said that Bova is more about driver training and safety tips for passengers on the effect of lubrication on the concrete pressure testing machine. (end)

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