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Rocket PID Controller


Different forces affect the movement of a rocket. The forces come from the nature of material used to construct/mass, environmental conditions and operational conditions e.g. rotational, which affects the performance. When the movement of a rocket is linear e.g. straight line/curve, it is easier to calculate and minimize errors. However, problems occur on instances whereby the rocket rotates. An array of equations and derivatives has been derived to understand the movement of the rocket on different scenarios with the aim of minimizing calculation errors. PID is commonly utilized in industrial control systems. It brings into consideration three errors, which are present error, past error and future errors all which are premised on current rate of change. Employing PID control on a rocket is important because it avoids calculation errors that are beyond normal or easier calculations.

Review of PID controller methods while understanding the movement of rockets

Method / Procedures

Different PID control systems exist and each of these systems are premised on differently operational requirements or conditions. Authors have presented unique PID control strategies based on their understanding and based on the industries they operate. The paper reviews the contribution of Korkmaz, Aydogdu & Dogan titled “Design and Performance Comparison of Variable Parameter Nonlinear PID Controller and Genetic Algorithm Based PID Controller”, and Keel, Rego & Bhattacharyya (2003). Keel, Rego & Bhattacharyya (2003) article is titled, “A New Approach to Digital PID Controller Design”. Important information are collected from these articles and used to understand how a rocket movement can be monitored and how errors are avoided/minimized.

Result / Discussion

Korkmaz, Aydogdu & Dogan (2012) proposes an idea in which a digital PID is designed for a plant based on arbitrary linear time. The authors employ unit circle root counting and Tchebyshev representation, whereby it is possible to calculate a two parameters that are unknown when the third parameter value is fixed. Through analyzing the known parameter, it is possible to stabilize the entire calculation. The importance of such approach allows determination of stabilization solution and it the situations of stabilization solution availability; it is possible to determine constructively any gains. Korkmaz, Aydogdu & Dogan with the defined approach were able to provide two design problems solutions. One of the solutions is the maximal delay tolerance, which is the maximal loop delay can tolerate PID control system. The second solution is the maximally deadbeat design is whereby closed loop system characteristic roots. Understanding maximal delay tolerance and maximally deadbeat design solutions are crucial in designing rockets. Advancement in technology requires redesigning of rockets since the environment and scientists aim to achieve specific goals. In utilization of the solutions and ideas that are premised on a single parameter that results in solutions for two parameters, it is easier to calculate and allow decay of errors in a faster rate.

On the other hand, Keel, Rego & Bhattacharyya (2003) compares the performance and design of Genetic Algorithm (GA), and nonlinear PID (NL-PID). System output and input error function is defined before commencement of the simulation, with the aim of obtaining variable coefficients of a given PID controller. In the same instance, another NL-PID controlled is design that has clearly defined error function. The non linear PID controller is able to manipulate parameters over a given time based on the output response. The GA-PID is also configured to perform similarly to the proposed NL-PID. The PID controllers that are designed based on Ziegler Nichols/NL-PID operates effectively (good performance) but they have numerous issues that include high exceeding and poor robustness. It is attributed to those instances when parameter changes, the entire control mechanism may perform dismally; such scenarios whereby PID parameters should be configured to fulfill the requirements proposed. Conversely, GA-PID parameters coefficients were calibrated based on objective function and the performance was better when compared to NL-PID. The GA-PID controllers reported better performance indices, short settling time and lower exceeds. Therefore, according to Keel, Rego & Bhattacharyya (2003) study, GA-PID is a better controller. According to the information, a GA-PID type of controller is appropriate for designing of a rocket. It is attributed to frequent environmental changes; for example, due to global warming and environmental concerns, it is difficult to calculate the impact of weather on utilization of rocket. Moreover, some of the earlier methodologies did not factor into consideration technological changes and methods such as Ziegler Nichols should be employed as a basis model, and a better method/approach obtained from the base model/method.


Rockets are sent to the space and utilized in an array of activities. While sending the rockets to the space, it has to deal with numerous parameters. The parameters ranges from drag, thrust to gravitational forces. In designing of the rockets, it is crucial to understand the use of the rocket and determine the nature of the environment in which it would pass. Sometimes, it is difficult to accurately calculate and determine the design and therefore, PID control are important in such situations. PID controls aims to address current errors, past errors and future errors based on current data. Researchers have seen the importance of PID methods in industrial settings and these researchers continue to define and design appropriate PID models. Researchers such as Keel, Rego & Bhattacharyya (2003) and Korkmaz, Aydogdu & Dogan (2012) have formulated and defined approaches towards understanding and appreciating PID controllers. The researchers factor into consideration numerous parameters while coming up or weighing on PID alternative controllers. Hence, no single PID controller is specific to certain environment because the parameters keep changing and therefore the design of rockets should factor information of the PID controllers. The PID controllers allow and define parameters that may be incorporated into a rocket.


Class Notes. Forces on a Rocket.

Keel, L., Rego, J., & Bhattacharyya, S. (2003). A new approach to digital PID controller design. IEEE Transactions on Automatic Control, 48(4), 687- 692

Korkmaz, M., Aydogdu, O., & Dogan, H. (2012). Design and performance comparison of variable parameter nonlinear PID controller and genetic algorithm based PID controller. IEEE.