Overview
A high complexity, high-coupled, driving force is smaller than the physical freedom of physical freedom, in order to realize the stable motion attitude control of the robot in space, this design puts the movement of the robot sports system in space The et al., Based on the motion characteristics of the model, the speed closed loop control algorithm and the angular closed loop control algorithm are designed, respectively, and the stable control of rotating paid in the space is achieved by double closed loop control algorithm.
Development environment
Hardware: This design hardware relies on the ART-PI development platform. The main control chip uses the STM32H750 high-performance single-chip microcomputer. At the same time, the TB6612 chip is used as the core power driver of rotating inverted, using the Hall sensor as a speed collection, using high-precision potentiometers as swing The arm angle acquisition sensor is used to display the display of the parameters using the OLED screen.
RT-THREAD version: The RT-THREAD version is 4.0.2
Development Tools and Version: MDK5.32 version
RT-THREAD Usage Overview
This design uses the RT-Thread 4.0.2 Master version, which is used for the full core, FINSH console interaction, SPI driver, ADC driver, encoder driver, PWM driver, etc., and writes double closed loop PID control. algorithm.
Software framework description
This design hardware platform is based on Art-Pi, the core part has been fixed, and the structure is shown in the mechanical part of the rotation, and the structure is shown below:
Software module description
The most critical part of this design is the implementation of the PID algorithm. For the motion characteristics of inverted pendulum, the optimization and adjustment is performed, and the PID algorithm is based on the theoretical basis of linear control in the classical control theory:
In the actual engineering actual application, the most widely used regulator control law is proportional, integral, differential control, referred to as PID control, also known as PID adjustment [6]. The PID controller has been in the past 70 years of history, which has become one of the main technologies of industrial control with simple structure, good stability, reliable work, and convenient adjustment. When the structure and parameters of the controlled object cannot be fully grasped or not, other techniques of the control theory are difficult to adopt, the structure and parameters of the system controller must be determined by empirical and field debugging.
In integral control, the output of the controller is proportional to the integral of the input error signal. For an automatic control system, if there is a steady state error after entering steady state, this control system is called a steady-state error or abbreviated system. In order to eliminate steady state errors, "integration item" must be introduced in the controller. The integral item is dependent on time, and the integral item will increase over time. This will increase even if the error is small, the integration item will increase over time, and it drives the output of the controller to further decrease the steady state error until it is equal to zero. Therefore, the proportional plus pose (PI) controller can make the system have no steady state errors after entering steady state. Be
Differential (D) control
In the differential control, the output of the controller is proportional to the differential (ie, the change rate of the error) of the input error signal. The automatic control system may have oscillation or even instability during the adjustment of the error. The reason is due to the presence of a large inertial component (link) or a hysteresis assembly, which has the effect of suppressing the error, and its change is always lagging behind the error. The solution is to make the effect of suppressing the effect of "super", that is, when the error is close to zero, the effect of suppressing the error should be zero.
That is to say, only "proportion" items in the controller are often insufficient, the proportional role is only the amplitude of the amplification error, and the "differential" is currently needed, it can predict the trend of error change, Thus, the controller with a proportional differential can make the control effect of the suppression error equal to zero, even negative values, thereby avoiding the serious ultra-tuning of the received amount. Therefore, there is a controlled object with greater inertia or lag, the proportional differential (PD) controller can improve the dynamic characteristics of the system in the adjustment process.
Demo effect
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Contest
This competition is basically a little bit of a little bit of spare time. The middle has encountered some difficulties. The main problem appeared on the underlying configuration of the chip, but through the comparison manual introduction and simulation, it can be initially solved. Thanks to the perfect core management, debugging interaction, driving design of the RT-THREAD operating system, so that there will be a lot of detours in the design, speeding up the development speed, I recommend everyone to try to use the system, really good.
Original title: [RT-THREAD work show] design and implementation of robot driver control model based on embedded operating system
Article Source: [WeChat public number: RTTHREAD IoT operating system] Welcome to add attention! Please indicate the source of the article. Read more
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