Design of an intelligent rescue robot

introduction

The reason why an intelligent robot is called an intelligent robot is that it has a fairly developed "brain". The central computer works in the brain, and this computer has a direct connection with the person who operates it. Most importantly, such a computer can perform actions arranged according to the purpose. Because of this, we say that this kind of robot is a real robot, although their appearance may be different.

Intelligent robots have a variety of internal and external information sensors, such as vision, hearing, touch, and smell. In addition to receptors, they also have effectors as a means of acting on the surrounding environment. These are muscles, or self-pacing motors, which make the hands, feet, long noses, tentacles, etc. move.

We call this robot an autonomous robot to distinguish it from the robots we have discussed above. It is the result of cybernetics, which advocates the fact that the purposeful behavior of life and non-life is consistent in many aspects. As an intelligent robot maker said, a robot is a functional description of a system that could only be obtained from the results of the growth of living cells in the past, but now they have become something we can make ourselves.

Since the publication of "Rossum's Universal Robots" by Czechoslovak writer Karel Capek in 1920, people have been full of fantasies and expectations about robots. With the continuous development of society, the division of labor in various industries has become more and more detailed, and robots can also play an important role in replacing people's labor. At the same time, with the development of science and technology, robots working in dangerous places such as exploration, disaster relief, and bomb disposal, as well as the application of robots in automated production are becoming more and more widespread. Therefore, the development of intelligent rescue robots has become urgent and necessary. This article discusses the design of intelligent rescue robots.

1 Hardware Design of Intelligent Rescue Robot

The intelligent rescue robot is mainly composed of six parts: power module, detection and sensing module (to realize line patrol, obstacle avoidance, coin picking and distance measurement functions), sound and light alarm module, controller module, motor drive module and display module. Its structural block diagram is shown in Figure 1.

1.1 Power Circuit

All the energy of the intelligent rescue robot comes from six AA batteries located at the bottom of the robot, which are used to power its single-chip microcomputer and peripheral sensors through the traditional 7805 voltage regulator circuit. The circuit is shown in Figure 2. Some sensors are powered by 5V low voltage to prevent the robot from detecting obstacles too early and stopping.

1.2 Detection sensor module

1.2.1 Line patrol circuit

We use infrared pair tubes for line patrol module. Infrared pair tubes are composed of LED and phototransistor. Phototransistor changes the active base current according to the intensity of LED light reflected from the ground. Connect a pull-up resistor to the base of phototransistor, and the intensity of reflected light can be determined by measuring the base voltage. Strong light means that the light below the detector is white, weak light means that the light below is weak, and most of the light is absorbed by the black line. For the output analog signal, we introduce it into five voltage comparators LM339 for processing.

1.2.2 Obstacle Avoidance Circuit

The obstacle avoidance part uses photoelectric switches, which are placed in all directions that the robot needs to measure. In order to reduce its measurement distance and ensure the normal operation of the robot, we use a low-voltage 5V power supply. Although the power supply voltage is slightly insufficient, it can ensure its normal short-distance detection. The high and low levels of the signal line of the photoelectric switch can reflect the presence or absence of obstacles in front. The obstacle detection circuit is shown in Figure 3.

1.2.3 Ultrasonic ranging circuit

Due to the characteristics of ultrasonic wave's strong execution, slow energy consumption and long propagation distance in the medium, we use DIP-ME007 ultrasonic ranging module to complete the height measurement function, and its circuit board is shown in Figure 4. DIP-ME007 ultrasonic ranging module can quickly and conveniently measure the distance between the bottom of the bridge and the ranging module. This module has five pins: VCC, tring, echo, out, and GND. The output of DIP-ME007 ultrasonic ranging module is pwm mode. After VCC and GND are connected, a high level of more than 10 s is sent to tring, and then the high level output can be waited for at the receiving port echo.

1.3 Controller Circuit

Since the main controller has many tasks, the circuit requires more pins, and the display control program is more complicated, we separately equipped a single-chip microcomputer as the auxiliary part of the main controller to share the work of the main controller and complete the work of the display part. The connection between the main controller and other modules is shown in Figure 5.

1.4 Sound and light alarm circuit

The sound and light alarm module is mainly used in the search and rescue alarm circuit. At the same time, in order to further expand the application, we introduced another signal line to control the sound while controlling its switch. To find coins, we use a metal detection sensor. When metal is found, the level on its signal line changes from low to high, triggering the interrupt of the microcontroller. Under the control of the microcontroller, the robot stops moving, starts the music generation module and lights up the LED for sound and light alarm. The specific implementation circuit is shown in Figure 6.

1.5 Motor drive circuit

The microcontroller controls the motor to rotate forward, reverse or stop through the feedback signal of the sensor to control the robot to complete various actions. L298N is a dedicated motor driver chip, which can realize multiple functions such as motor forward and reverse rotation, braking, PWM speed regulation, etc. It is an ideal chip for controlling robot motors, so we use L298N chip to control two ordinary motors. The L298N chip signal power supply and drive power supply are separated, and the voltage of the motor can be adjusted as needed. Its drive circuit is shown in Figure 7.

1.6 Display Circuit

The MSl602C-1 LCD is used to display the corresponding information. The operating voltage of this display module is about 5V, and it supports displaying 2 lines of characters, each line can display 16 characters, and each character is displayed by a 5×7 dot matrix.

Since the main controller's microcontroller has many tasks and the circuit wiring is complex, we use a separate microcontroller to control the display module.

2 Software Design of Intelligent Rescue Robot

The software control part of this intelligent rescue robot is programmed in C language, and the powerful functions of C language are used to realize the control function of the single-chip microcomputer AT89S52. The main program flow chart is shown in Figure 8.

3 Conclusion

With AT89S52 single-chip microcomputer as the core component, using infrared sensor detection, motor control and other technologies, through discussions and attempts of various solutions, and after multiple rounds of overall hardware and software debugging, the system is continuously optimized. Finally, the intelligent rescue robot can achieve the following functions: avoid obstacles and find a suitable path; smoothly pass the damaged bridge and can accurately measure the height of the bridge; automatically identify the route status, and make quick judgments based on the real-time status to accurately control the robot's steering; automatically display the required information; automatically find the line and move forward, and can intelligently detect, pick up and put down coins; sound and light alarms, and colorful lights flash; automatically stop at the specified location and display the end of the rescue.