汽车控制系统-无程序翻译

汽车控制系统-无程序翻译 基于单片机AT89C51的汽车智能安全控制系统的设计和研究 Design and research of automobile intelligence security control system based on microcontroller AT89C51 摘要:本文以AT89C51为主要控制芯片，对汽车行驶过程中的行驶速度，行驶 时的刹车和离合器根据实际情况实行控制。通过一个远距离的位移传感器， 检测 工程第三方检测合同工程防雷检测合同植筋拉拔检测方案传感器技术课后答案检测机构通用要求培训 车身和前面障碍物之间的距离，根据车子当时的行驶状况(包括行驶速度，最大 加速度——路面的粗糙程度)对车子的速度(刹车和离合器)实现自动控制，使 汽车能够在安全的速度下行驶。 关键字:AT89C51;位移传感器;刹车;离合器 Abstract: In this paper, AT89C51, as the main control chip, controls the auto speed, brake and clutch while traveling under some situation. A long-distance displacement sensor can detect the distance between the sensor itself and the obstacles in front of it, and succeed in autocontrolling the speed (brake and clutch) according to its traveling condition (including speed, maximum acceleration - the roughness of the pavement), which ensure that autos travel at the safe speed. Keywords: AT89C51; Displacement sensor; Brake; Clutch 1.引言 随着社会的进步和人民生活水平的提高，汽车作为日常交通工具，在我们的 生活中起到愈来愈重要的作用，可以预言:在不久的将来，小汽车将会进入每家 每户，将成为今后我们生活中必备的交通工具。当然与此同时车辆的行驶安全也 将被我们越来越重视。怎样确保汽车行驶过程的安全，将是我们必须首先解决的 问 题 快递公司问题件快递公司问题件货款处理关于圆的周长面积重点题型关于解方程组的题及答案关于南海问题 。近年来尽管我国的汽车交通死亡人数呈下降趋势，但每年仍有约10万人 死于车祸。我国汽车交通事故造成的死亡和社会经济损失是汽车与交通安全领域 急需解决的社会问题。 1. Introduction With the advancement of society and improvement of people’s living standard, automobiles become the ordinary vehicles and play the more and more important role in our lives. It can be predicted that the car will enter into every household and become our necessary vehicle in our future life. Meanwhile, we will pay more and more attention on the driving security. The problem we should first solve is how to ensure the security of auto traveling. Although the number of casualties in traffic accidents has the tendency of decline, approximately 100,000 people died of traffic accidents every year. The death and economic loss resulting from traffic accidents is the social issue in the field of transportation safety, which presses for solution. 2.基本原理 本设计的基本设计思想是利用远距离位移对正在行驶的汽车前面与障碍物 进行距离检测。检测结果经过A/D转换器转换后输入到单片机, 和当前行驶的速 度、路面的粗糙程度(通过传感器进行测量)进行综合计算后, 对输出结果经过 数模转换后, 对汽车的刹车和离合器实行自动控制。 2. Basic theory The basic idea of this design is to detect the distance between the automobile and the obstacles in front of it, making use of a long-distance displacement sensor. After the detecting result is transformed by A/D converter, it will be inputted into microcontroller and then after the computed with the current traveling speed and the roughness of the road (measured by sensor), whose output result will succeed in autocontrolling brake and clutch after A/D transformation. Basic theory of system is shown in Figure1.1 系统的原理图如图1.1 图1.1车安全控制系统的原理图 Figure 1.1 Basic theory of security control system 3.硬件电路的设计 3.1主要元器件及芯片的选择 3. Hardware circuit design 3.1 Section of main components and chips 3.1.1 Using microcontroller AT89C51 in MCU AT89C51 is 8-bit microcontroller with low voltage and high performance made by American ATMEL company, which includes 4k bytes erasable ROM and 128 bytes RAM, compatible with MCS-51 command system, and which is [1]planted with a general 8-bit central processor and Flash memory cell. 3(1.1MCU选用单片机AT89C51 AT89C51是美国ATMEL公司生产的低电压，高性能的CMOS 8位单片机， 片内含4k bytes的可反复擦写的只读程序存储器和128bytes的随机数据存储器， [1]兼容MCS—51指令系统，片内置通用8位中央处理器和Flash存储单元。 Main performance parameters: Completely compatible with MCS-51 command system 4k bytes erasable Flash celerity memory 1000 erasing periods Full static operation:0Hz——24MHz Three- step encrypted procedure memory 128*8 –bite interior RAM 32 programmable I/O rim lines Two 16-bit timers 6 interrupters interrupt source Programmable serial UART channels Low power dissipation free and power-fall mode 主要性能 参数 转速和进给参数表a氧化沟运行参数高温蒸汽处理医疗废物pid参数自整定算法口腔医院集中消毒供应 : 与MCS—51的指令系统完全兼容 4k字节可重擦写Flash闪速存储器 1000次擦写周期 全静态操作:0Hz——24MHz 三级加密程序存储器128*8字节的内部RAM 32个可编程I/O口线 2个16位定时器 6个中断源 可编程串行UART通道 低功耗空闲和掉电模式 3.1.2 Long-distance displacement sensor Distance sensor DLS-B Based on the existing DLS-A measuring distance sensor, DLS-B will improve measuring response speed. Its quickest dynamic response can attain 25Hz and the longest measuring distance can achieve 500m, the highest precision is 1.5mm. 3.1.3 Selecting of A/D converter and D/A converter Using ADC0804 as A/D converter: ADC0804 is a comparative A/D conversion chip, made byCMOS integration technique, whose resolution is 8-bit, conversion period is 100μs and input voltage range is 0-5V, and which can attain 5V after adding some exterior circuits. Output data latch register is fixed in the chip, whose conversion circuit output can be connected to CPU directly while it is linked with computers. 3.1.2远距离位移传感器 距离传感器DLS-B DLS-B系列在原有DLS-A系列测距传感器上,提高了测量响应速度，开创性 的动态响应时间最高可达25Hz，最长测量距离(需反射板)可达500m，最高精 度达1.5mm。 3.1.3A/D转换器的选择和D/A转换器 A/D转换器选用ADC0804: ADC0804是用CMOS集成工艺制成的逐次比较型摸数转换芯片。分辨率8位， 转换时间100μs，输入电压范围为0~5V，增加某些外部电路后，输入模拟电压 可为 5V。该芯片内有输出数据锁存器，当与计算机连接时，转换电路的输出可 以直接连接在CPU数据总线 Using DAC0832 as D/A converter: DAC0832 is made up of an 8-bit input register, an 8-bit DAC register and an 8-bit D/A converter which uses inverted ‘T’ type R-2R resistor network. Because DAC0832 has two data registers which can be controlled respectively, it has much more flexibility than many others and can pick up different ways of working as needed. Without operational amplifier in DAC0832 and with current output in DAC0832, the external operational amplifier needs using while working. With Rfb set in the chips, 9 feet can be connected to output point. If the operation amplifier gain is not enough, the external feedback resistor should be fixed. D/A转换器选用DAC0832: DAC0832由一个八位输入寄存器、一个八位DAC寄存器和一个八位D/A转 换器三大部分组成，D/A转换器采用了倒T型R-2R电阻网络。由于DAC0832 有两个可以分别控制的数据寄存器，所以，在使用时有较大的灵活性， 可根据 需要接成不同的工作方式。DAC0832中无运算放大器，且是电流输出，使用时须 外接运算放大器。芯片中已设置了Rfb，只要将 9 脚接到运算放大器的输出端 即可。若运算放大器增益不够， 还须外加反馈电阻。 By logical analysis of interior control in DAC0832, LE1 is in high voltage while ILE, CS and WR1 are effective simultaneously. Meanwhile, input data D7~D0 enter into input register. While WR2 and XFER are effective simultaneously, LE2 is in high voltage. Meantime, and the data in input register enter into DAC register. 8-bit D/A converter circuit is ready to convert the data in DAC register [2]into Analog signal(IOUT1+IOUT2)to output. 从DAC0832的内部控制逻辑分析可知，当ILE、CS和WR1同时有效时， LE1为高电平。在此期间，输入数据D7~D0进入输入寄存器。当WR2和XFER 同时有效时，LE2为高电平。在此期间，输入寄存器的数据进入DAC寄存器。 八位D/A转换电路随时将DAC寄存器的数据转换为模拟信号(IOUT1+IOUT2) [2]输出。 Besides, a multiple selector is fixed at the analog signal input point to select signals (the distance between auto and the front obstacle and the present pavement condition). Performing system should select the actuator which can control better. With the increasing of inputting analog signal, control intensity should increase linearly or exponentially. 此外，本设计还需要一个路选择器在模拟信号输入端对模拟输入信号(车子 与前面障碍物的距离和当前路面状况)进行选择。执行机构应该选用控制效果比 较好的执行器，比如随着输出模拟信号的增加，控制强度最好应该是线性增加或 是。 3.2 Connection Circuit between main components Because input signals of the sensor are always weaker and have the strong interference, the voltage signals detected by sensors will first pass wave filter circuits and amplifier circuits and then input ADC. This design is required to detect two signals (the distance between auto and front obstacle and the roughness of the pavement), and both quantities must ADC and input MCU, therefore a 2-crucuit sector is fixed to connect ADC and 2-crucuit input, so that MCU can control when to input distance and when to input roughness. (This circuit will not be introduced in detail here.) 3.2 主要元器件之间的连接电路 传感器的输出信号一般都比较弱，而且带有比较强的干扰，所以通过传感器 检测到的电压信号首先要经过滤波电路和放大电路，然后输入到模数转换器进行 模数转换，由于本设计需要检测两个信号(车子与前面障碍物的距离和车子当前 行驶的路面的粗糙状况)，而且两个量都需要通过模数转换，输入到单片机，所 以在模数转换器与两路输入之间应该接一个二路选择器，有单片机来控制何时输 入距离，何时输入粗糙程度。(此电路在这里不做具体介绍)。 3.2.1 Connections between ADC and MCU The function of this part is to convert two detected physical quantities (the distance between auto and front obstacle and friction level between autos and pavement) into digital quantities and then to deposit them in the corresponding memory in the MCU, which is helpful to compute these data, and then achieve the appropriate control of external actuator. Specific circuits are as shown in Figure 3.1: 3.2.1模数转换器与单片机之间的连接 此部分的功能是把外面检测到的两个物理量(车子与前面障碍物的距离和车 子与地面的摩擦程度)转换成数字量存入单片机相应的存储器中，以便根据这些 数据进行相应的运算和控制，以便实现对外部执行机构实行相应的控制。 具体电路图如图3.1所示: 图3.1数模转换器与单片机AT89C51之间的连接图 Figure 3.1 Connections between ADC and MCU AT89C51 AT89C51 controls the conversion of ADC0804 through P3.0,P3.1,P3.2,P3.3. thThe 6 pin is connected to input point of 2-crucuit sector, while 9th pin is linked to reference voltage. And then the conversion result is inputted to internal MCU through P1. 3.2.2 Connection between MCU and DAC and control of actuator It is digital signal that MCU output, so outputted digital signal must be converted into analog signal by DAC in order to control the braking action of autos. Other circuits are shown in Figure 3.2 AT89C51通过P3.0,P3.1,P3.2,P3.3对ADC0804实行转换的控制。ADC0804 的第6管脚接二路选择器的输出端，第9管脚接基准电压。转换后的结果又单片 机的P1口输入到单片机内部。 3.2.2单片机与数模转换器之间的连接与执行机构的控制 单片机输出的是数字信号，要想去控制车子的刹车动作，应该把输出的数字 信号经过数模转换，转换成模拟信号。 其电路图如图3.2所示 图3.2 单片机与数模转换电路的连接图 Figure 3.2 circuits of connection between MCU and DAC 3.2.3 Control circuits of brake and clutch For the brake and clutch, we take different controlling methods. For the clutch, we control it by simple 2-valued logic. (Either completely separated or not separated) When the car maintains the safe distance from the obstacle in front of it, the clutch isn’t used. When the distance between autos and obstacle is too small, we use complete clutch and it can separate the power system and auto, which is able to avoid many dangerous traffic accidents. For example, when drivers feel nervous facing with coming accidents, they would step on accelerator instead of brake. Even if drivers make a mistake in the operation and they mistake accelerator for brake, the auto will slow down by the friction between road surface and the auto itself because the auto power system is separated from wheel drive system, thus avoiding unexpected accidents as result of drivers’ wrong operation increasing the auto power. 3.2.3 刹车和离合器的控制电路图 对于车子的离合器和刹车，我们采用不同的控制方式。 对于离合器我们采用简单的二值逻辑进行控制(要么实行完全离合，要么不 离合)，当车子和前面的障碍物在安全的距离范围内时，我们不对车子离合。当 车子与前面障碍物的距离太小时，我们实行完全离合，把车子的动力系统与车子 完全分离开，这样就可以避免很多比较危险的交通事故，比如由于驾驶员的在面 对马上可能会来临的车祸而紧张，误把油门当刹车踩的情况，即使是由于驾驶员 的误操作，把油门当成了刹车踩，但是由于汽车的动力系统已经与车轮的驱动系 统彻底分开，汽车只会在车子本身与路面之间的摩擦作用下慢慢停下来，而不会 因为驾驶员的误操作而给汽车增加动力，使之发生意想不到的车祸。 As for the control of brakes, this design is to control braking degree through frequency transformer according to output variable of ADC. When the clutch is not separated completely, the brake doesn’t implement stopping; when the clutch is separated completely, braking actuator determines whether to brake and the braking degree according to output variable of ADC, thus ensuring the safe driving of autos. Control circuit of baking is shown in Figure 3.3 对于刹车的控制，他是根据数模转换器的输出量的大小，通过变频器对刹车 程度进行控制。并且在离合器没有被完全离合之前，刹车没有执行制动，当离合 器被完全离合之后，刹车执行机构根据数模转换器的输出量的大小来决定对刹车 实行制动和制动的程度。从而确保汽车可以安全行驶。 刹车控制电路图如图3.3所示: 图3.3 刹车控制电路图 Figure 3.3 Control circuit of baking 4. Software design of controlling system Running of AT89C51 must be controlled by the corresponding program. The program is made up of the following main parts: read external distance data, read degree of road surface friction, process external input data, control auto’s [3]clutch and brake. The program flow chart is shown in Figure 4.1: 4(控制系统软件设计 AT89C51的运行必须由相应的程序对他实行控制，程序主要包括一下几个部 分:外部距离数据的读取，路面摩擦程度的读取，对外部输入数据的处理，控制 [3]汽车的离合器和控制汽车的刹车。 程序 流程 快递问题件怎么处理流程河南自建厂房流程下载关于规范招聘需求审批流程制作流程表下载邮件下载流程设计 图如图4.1所示: 图4.1控制程序流程图 Start System initialization Read distance data Read degree of road surface friction data processing whether driving within the safe distance Control clutch whether driving within the safe distance Control brake 5. Conclusion This design, most of which is founded on the basis of consumption, is restricted to the theoretical research owing to the limited conditions. For example, sensor of distance test will change with the external conditions (temperature, visibility etc.) Moreover, the corresponding control rules, in particular the stopping extent of brake, should be modified in the practical applications. 5.结论 本设计由于条件的限制，只是限制在理论研究方面，很多都是建立在假设的 基础上，比如距离的测试传感器会随着外界的条件(温度，能见度等)变化而有 所变化。相应的控制规则，尤其是刹车的制动程度，应该在实际的应用中进行修 正。 参考文献: [1] 张毅刚.单片机原理及应用[M].高等教育出版社，2006 [2] 龚之春. 数字电路[M].电子科技大学出版社，1998 [3] 张齐，杜群贵.单片机应用系统设计技术[M].电子工业出版社，2004 References: [1] Zhang Yigang. Microcontroller theory and application[M]. Higher education press, 2006 (in Chinese) [2]Gong Zhichun. Digital Circuit[M].University of electronic science and technology press, 1998 (in Chinese) [3] Zhang Qi, Du Qungui. Microcontroller application system design technology[M].Electronics industry press, 2004 (in Chinese)