“Autonomous mobile robot system refers to an intelligent system that performs autonomous path planning based on command tasks and environmental information, and continuously collects local environmental information during task execution, makes decisions, so as to achieve safe driving and accurately reach the target location. This article is based on In order to control HX, LPC2119 introduces a design scheme of a wheeled mobile robot. The robot system uses ultrasonic sensors, photosensitive sensors, and collision sensors to collect external environmental information, and uses PTR2000 to realize the communication between the mobile robot and the computer, so as to realize the feedback and feedback of on-site information. The computer controls the sending of commands.

“Autonomous mobile robot system refers to an intelligent system that performs autonomous path planning based on command tasks and environmental information, and continuously collects local environmental information during task execution, makes decisions, so as to achieve safe driving and accurately reach the target location. This article is based on In order to control HX, LPC2119 introduces a design scheme of a wheeled mobile robot. The robot system uses ultrasonic sensors, photosensitive sensors, and collision sensors to collect external environmental information, and uses PTR2000 to realize the communication between the mobile robot and the computer, so as to realize the feedback and feedback of on-site information. The computer controls the sending of commands.

Autonomous mobile robot system refers to an intelligent system that performs autonomous path planning based on command tasks and environmental information, and continuously collects local environmental information during task execution, makes decisions, so as to achieve safe driving and accurately reach the target location. This article takes LPC2119 as the control HX, and introduces a design scheme of a wheeled mobile robot. The robot system uses ultrasonic sensors, photosensitive sensors, and collision sensors to collect external environmental information, and uses PTR2000 to realize communication between the mobile robot and the computer, so as to realize the feedback of on-site information and the sending of computer control commands.

LPC2119 is an arm7TDMI-S microprocessor that supports real-time simulation and tracking introduced by Philips, and is embedded in 128KB high-speed Flash memory. It uses a three-stage pipeline technology, fetching instructions, decoding and executing at the same time, can process instructions in parallel, and improve CPU operating speed. Due to its very small size and low power consumption, it is very suitable for miniaturized applications. The on-chip SRAM up to 64KB has a large buffer size and powerful processing capabilities. LPC2119 integrates 2 CAN controllers, 2 32-bit timer counters and 4 ADC unit circuits.

Design of PWM control circuit of motor

IR2110 is a dual-channel, high-voltage, high-speed monolithic integrated driver for the gate drive of power devices launched by the American IR company. It integrates most of the functions required to drive the high-side and low-side MOSFETs or IGBTs in a high-performance package, and it can provide extremely fast switching speeds and extremely low power consumption with a few external discrete components. Its characteristics are: convert the input logic signal into the same phase low impedance output drive signal, which can drive 2 outputs on the same bridge arm, with strong driving ability and fast response speed; high working voltage, up to 600V; built-in undervoltage Blocked; low cost and easy to debug; the circuit chip is small in size and is packaged in DIP14. The high-voltage side drive uses an external bootstrap capacitor to power up. Compared with other IC drive circuits, the design greatly reduces the number of drive transformers and capacitors, reduces product costs, reduces volume, and improves system reliability. This bootstrap integrated circuit suitable for driving power MOSFETs and IGBTs has been widely used in power drive fields such as power conversion and motor speed regulation.

The PWM function of the LPC2119 microcontroller is based on a standard timer. It has a 32-bit timing controller and a prescaler controller, and 7 matching controllers. It can realize 6 unilateral PWM or 3 bilateral PWM outputs, and it can also be used These two types of mixed output. This system uses ports PWM0 and PWM1 to output two PWM signals to control the two driving motors of the mobile robot respectively. The PWM signal forms two signals with a phase difference of 180? through the photocoupler and adds them to the HIN and LIN pins of the IR2110 to realize the control of the two MOSFET switches on the same bridge arm. The principle is shown in Figure 1.

Circuit Design of Autonomous Mobile Robot Based on ARM

When HIN is high level, Q1 and Q4 are turned on, and positive working voltage is applied to the DC motor; during HIN is low level, LIN terminal is input high level, Q2 and Q3 are turned on, and the reverse direction is applied to the DC motor. Operating Voltage. Therefore, the working voltage on the armature is a bipolar rectangular pulse waveform. Due to the mechanical inertia, the average value of the rectangular pulse voltage determines the steering and speed of the motor.

Ultrasonic sensor system

In order to reduce the burden of the controller LPC2119, the ultrasonic sensor system is controlled by the AT89C1051 microcontroller of Atmel. The 1051 microcontroller is a high-performance microcontroller with a 1KB programmable E2PROM, which is compatible with the instructions and pins of the industry standard MCS-51. It provides a highly flexible and effective solution for many embedded control applications. AT89C1051 has the following features: 1KB of E2PROM, 128B of RAM, 15 I/O lines, 2 16-bit timer/counters, 5 secondary vector interrupt structures, 1 full bidirectional serial port and contains precision analog comparison The device and the on-chip oscillator have a voltage working range of 4.25~5.5V and a working frequency of 24MHz. At the same time, it also has an encrypted array of secondary program memory lock, power down and clock circuits. In addition, AT89C1051 also supports two power saving methods set by software. When idle, the CPU stops, while the RAM, timer/counter, serial port, and interrupt system continue to work. When the power is off, the content of RAM is saved, but the oscillator stops oscillating to prohibit other functions of the chip until the next YC hardware reset.

1051 controls to send an ultrasonic wave every 60ms to detect the echo time and complete the distance calculation. In this way, the 16-channel ultrasonic loop detection YC is about 1s, and the ultrasonic speed is about 344m/s at room temperature. The distance of the obstacle can be calculated, and the ZH transmits the ultrasonic sensor number and distance information to LPC2119. The ultrasonic transmitter and receiver subsystem is shown in Figure 2. 1051 uses the P1.0 pin to send out a 40kHz pulse signal, which is used as the enable signal of the 4-16 decoder 74HC154, and the pins P1.1~P1.4 are used as decoding signals, corresponding to the numbers 0~15 Ultrasonic sensor. This signal is amplified by 9013 and pushes the transducer to produce a 40kHz ultrasonic signal.

Circuit Design of Autonomous Mobile Robot Based on ARM

LM567 is a phase-locked loop circuit. The external resistance and capacitance of its 5 and 6 pins determine the center frequency f2 of the internal voltage-controlled oscillator, f2≈1/1.1RC. Pins 1 and 2 are grounded through capacitors to form an output filter network and a loop single-stage low-pass filter network. The capacitor connected to pin 2 determines the capture bandwidth of the phase-locked loop: the larger the capacitance value, the narrower the loop bandwidth. The working voltage of LM567 is 4.75~9V, the working frequency is from DC to 500kHz, and the static working current is about 8mA.

This design is a vehicle-mounted embedded system based on arm7 microprocessor, which not only meets the requirements of the mobile robot control system, but also provides good technical support for the transformation and application of the robot. On this basis, various advanced control algorithms can be added to realize the intelligentization of mobile robots.

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