Today, technological systems are designed to meet growing requirements in terms of safety and performance. This is particularly important for safety-critical applications such as aviation, aerospace or nuclear systems. Even a small, unnoticed and seemingly insignificant error or incorrect reaction to the error can lead to catastrophic failure of the entire system. New control techniques and design approaches are being developed to avoid fatal failures. These new techniques and approaches are also capable of tuning the required performance levels, including the stability of the overall system in addition to the ability to handle system faults. Such control systems are called fault-tolerant control systems. The ability to achieve a certain level of system performance upon the occurrence of a fault in the system components is a sign of a certain degree of redundancy in the system. However, achieving the performance level may be limited by physical or economic means. An effective solution to this situation is to reduce the system performance requirements. Sometimes the requirements need to be reduced to stabilizing only the most important parts of the system. When a fault occurs in one actuator, the entire system and its performance depend on the rest of the actuators and their performance, etc. and its performance depends on component limitations. It is therefore important to avoid excessive load on the actuators and therefore any risk of system failure. Often, the remaining actuators are used to reach the system state considered safe instead of continuing the task. The paper presents three different methods of reconfiguring the control using virtual actuators that stabilize the system with the faulty actuator. The control algorithms along with the conditions... middle of paper ...... another actuator is added in the following simulations to replace the actuator in case of failure so that the number of outputs of the system is equal to the number of entries. The extended nominal system and the extended system with default are used in the same way as in the previous part. In case of failure of the first actuator, all state space variables are stabilized at the desired values ​​without permanent control deviation after the start of the virtual actuator within 70 seconds. The system responses can be seen in the following figure. Further virtual actuator simulations with integral part are performed with an extended system upon failure of the third and fourth actuator. The weak reconfiguration objective is achieved in the same way as in the previous part. Controlled variables reach the desired values, but uncontrolled variables stabilize at non-zero values. The simulation results are summarized in the following table.