Traffic light and design specifications, traffic light design specifications

Traffic light and design specifications, traffic light design specifications

When crossing the road, I suddenly noticed the traffic lights, and the recent new traffic rules were also in full swing, So I thought about the "design specifications.

When it comes to design specifications, many people think it is a very virtual and not pragmatic performance project. Many enterprises design specifications for design specifications, set rules with their heads, and put their energy into it, and finally died. In the past, I was reluctant to develop design specifications. After suffering from the design of multiple terminals, I gradually understood the significance of the design specifications "existence is reasonable. A front-end UI framework that can improve development efficiency by 500%!

 

Revelation of traffic lights

Before you talk about it, let's go back to the traffic lights:

This is another common traffic light. When the industrialization and urbanization reach a certain level, and complex traffic is like a horse or a dragon, traffic lights also emerge. Here, the traffic lights play a normative role. passers-by and drivers reach an agreement that the red light stops and the green light goes. Everything goes in order. Without it, crossing the road will become thrilling.

This is a simple and common sense, but the migration of the same thinking to design will lead to a lot of interesting thinking.

It is often seen that product design teams often have heated discussions on interaction issues such as navigation and feedback. Although multi-element collision is a good thing, once the system starts to be large, the problem will also be exposed: the team members have their own creative pursuits, especially those who consider innovation as life. The pursuit of Rule innovation is even more prominent. If the team lacks the consensus and design constraints such as "Red Light stops and green light goes, this will lead to unordered superposition of rules, making the overall interaction of the software messy and complex. A front-end UI framework that can improve development efficiency by 500%!

 

Three sins of design specifications

1. Too early/too late for Standardization

The road in a small village does not need traffic lights, because they are not needed at all. The existence of traffic lights limits people's freedom to move around. However, there is a type of company that, when its products grew up in an early age and its scale was small, it took a lot of effort to develop design specifications early, but it was unacceptable and difficult to implement. It is neither too early nor too late. Large Companies may make such mistakes, such as google and android, which had a very rough and absent standard before 4.0, the problem will not be detected until your system runs many iPhone-like apps.

2. The specifications are too detailed

The traffic light is a simple "constraint". When the red light stops and the green light goes, you can decide how to stop and how to proceed. The makers of iPhone Design Guideline are very insightful. They chose a broad expression when writing specifications, there is no definition of how big the "click button" should be, there is no definition of "Return button" must be long in the upper left corner, there is no definition of deletion, there must be an animation thrown into the bin... The finer the expression, the larger the limit, will become the shackles of design team innovation.

3. The specifications remain unchanged

There were only two colors to replace in the early periods of traffic lights, but there was still some danger, after continuous improvement, a three-color signal lamp consisting of red, yellow, and green has been in use until now (some people have come to deny the yellow light ). The traffic lights are no longer a simple color replacement, but a complete signal system, sidewalk, Lane, with direction instructions... The same is true for design specifications. When the product becomes more complex and as big as a giant such as QQ, the specifications will be gradually improved and clarified to ensure the consistency of experience. The establishment of specifications is a long-term process. Broad design guidelines should keep pace with the times.

 

Big guidance and small specifications

Prior to the formal discussion, many predecessors have made various kinds of thinking and debate. As for implementation, the team may also have different projects.

Taking iPhone product design as an example, Apple's official iOS Human Interface Guidelines (formerly called iPhone Human Interface Guidelines) comparison system, many product designs directly refer to this document to build their own apps. The only design specification in the product lifecycle is this ready-made reference. In addition to the official design guidelines, we will also refine the design specifications to 1 + 1 (platform specifications and application specifications) based on the project requirements) to sort out the complex interaction details of the software.

Standardized case (1): Information System

As a small part of the software design, the prompt system won't be noticed by many teams. In the past, we had a complete information prompt system, which divided the prompts into four categories: A front-end UI framework that can improve development efficiency by 500%!

3.0 during the design process, we optimized the entire system, removed the Toast prompt, and unified the Banner Tips into a style, directly under the navigation bar.

Standardized case (2): Menu System

Menus are another common interactive system in software design. When our first version came out, we used a concealed (slide) design menu. After several versions of evolution, the appearance of menus is more direct and easier to expand, and provides explanations for non-operational exceptions.

 

IPhone QQ music is now a huge product, with a massive music library, information organization, personal music Asset Management, and basic playback experience ....

In addition to the above information prompts and menu systems, we also provide some simple guidelines for some common interaction systems of the product, including:

1. Navigation: defines global navigation rules, including normal Hierarchical Access, temporary interface, interface interadjustment, and cross-product interadjustment

2. Exception Handling: alerts and guidance for network interruptions and empty content .. A front-end UI framework that can improve development efficiency by 500%!

3. Brand communication: Visual Communication of music brands in terms of exceptions, Edge Conditions, and product slides

Of course, if something cannot be met, we will review it and adjust it in time. An efficient and controllable interaction system needs to change.

Finally, since most custom specifications have little significance (except for platform-level specifications), why should we put a lot of effort into it? In fact, the cost of small specifications other than the official specifications is very low. You do not need to organize a complete Style Library, but simply list the specifications on a large image, for reference by team members or intermediate designers. Mobile Internet products with extremely fast pace are simple and most vital.

A complete traffic light PLC design requires a diagram and a simple principle

Application of Micrologix1000 PLC in traffic light control
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PLC Technology and Its Application in Highway Transportation System
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Implement Intelligent Traffic Control Using PLC
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1 Introduction
According to incomplete statistics, at present, most traffic systems at intersections in Chinese cities are controlled on a regular basis (it is not ruled out that traffic police are used to replace traffic signals during busy road sections or peak hours ), this will inevitably lead to the following drawbacks: when a road section has a large traffic volume, it will have to wait for a red light, while the other road is an empty road or road with a relatively small traffic volume, but it will be a green light for a long time, this kind of embarrassment is caused by the absence of real-time monitoring of the actual situation, which not only makes drivers and passengers complain, but also wastes both human and material resources.

Intelligent Control of traffic systems is the current research direction and has made many achievements. In a few advanced countries, intelligent control of traffic signals has been adopted, mainly using GPS Global Positioning System. For the sake of convenience and effectiveness, we can use the following scheme to control traffic conditions: Make a sensor to detect the number of vehicles to control the traffic light duration. The details are as follows: the induction coils are embedded in the underground near all directions at the entrance. When the automobile passes through, eddy current loss will occur, and the inductance of the ring insulated wire will be reduced, the vehicle pass can be detected, and the signal is converted into a standard pulse signal as the control input of the programmable controller, and the duration of the traffic light is automatically adjusted according to certain control rules by using the PLC count.

Compared with the traditional timed traffic light control and intelligent traffic light control, we can see that the biggest advantage of the latter is to slow down the phenomenon of slow flow, and there will be no empty road occupation, which improves the highway traffic pass rate, the cost is lower than that of the Global Positioning System.

Design of a half-busy traffic light

4.2.2 traffic light hardware circuit diagram

4.2.3 System Operating Principle
(1) switch the keyboard to input the initial time of the traffic light, and input it to the system through the 8051 MCU P1
(2) The timer of the 8051 microcontroller sends information to the 8255 data port through the P0 port every second, And the 8255 PA Port displays the red, green, and yellow lights; the ignment time of each lamp is displayed on the PC port of 8255.
(3) 8051 set the lighting time of each signal and 8031, the green and red time are respectively 60 s, and the 80 s cycle is from the 8051 P0 port to the 8255 data port.
(4) The P3.0 bit of the 8051 single-chip microcomputer is used to control the system operation or set the initial value. When the card number is 0, the system is initialized and starts to work when the system is 1.
(5) Red Light countdown time. When a vehicle experiences a red light, start the buzzer to send an alarm. After 3 s, the system returns to normal.
(6) added the traffic flow detection function for each green light time, and queried whether the P2.0 port level is low. When the switch is pressed to a low level, the two-digit digital tube shows the traffic flow, until the next green time is rerecorded.
(7) the countdown to the green light time is complete and the cycle is repeated.
5. Software Design of the Controller
5.1 per second setting
There are two kinds of delay methods, one is to use the Internal timer of the MCS-51 to generate overflow interrupt to determine the time of 1 second, the other is to use soft delay method.
5.2 hardware latency of counters
5.2.1 counter Initial Value Calculation
When the timer is working, the initial counter value must be sent to the counter. This value is sent to TH and TL. It is an addition note, and can automatically generate overflow interruption requests from full 1 to full 0. Therefore, we can set the Count value required for the counter to zero to C and the initial count value to TC. The following formula can be obtained:
TC = M-C
In formula, M is the counter touch value, which is related to the counter work mode. When the mode is 0, M is 213; when the mode is 1, M is 216; when the Mode 2 and 3 is 28
5.2.2 Calculation Formula
T = (M-TC) T count
Or TC = M-T/T count
The T count is 12 times the clock cycle of the microcontroller TCLK; the TC is the initial value
For example, if the main pulse frequency of a single-chip microcomputer is TCLK12MHZ
Method 0 TMAX = 213*1 microsecond = 8.192 milliseconds
Method 1 TMAX = 216*1 microsecond = 65.536 milliseconds
Obviously, one second has exceeded the maximum counter time, so we can solve this problem only by combining the timer with the software.
5.2.3 1 second method
We set a software counter with an initial value of 20 in the main program and set the T0 time to 50 milliseconds. in this way, the CPU responds to its overflow interrupt request every time T0 to 50 milliseconds and enters its interrupt service subroutine. In the interrupt service subroutine, the CPU first reduces the software counter by 1 and then determines whether it is zero. 0 indicates that the output time display program can be returned after 1 second.
5.2.4 corresponding program code
(1) Main Program
The timer MUST be scheduled for 50 milliseconds, so T0 works in Mode 1. Initial values:
TC = M-T/T count = 216-50 ms/1us = 15536 = 3 CBOH
ORG 1000 H
START: mov tmod, #01 H; set TO Timer mode 1
MOV TH0, # 3CH; mount the initial value of the timer
MOV TL0, # BOH;
Mov ie, #82 H; open T0 interrupt
Sebt tro; Start T0 counter
Mov ro, #14 H; initial value assigned by the software counter
LOOP: SJMP $; waiting for interruption
(2) interrupt service subroutine
ORG 000... the remaining full text>