This study focuses on fault detection and diagnosis in robot arms using two methodologies: Discrete Wavelet Transform (DWT) and Slantlet Transform (SLT). The results indicate that the SLT combined with a Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) offers superior performance, achieving 100% accuracy and lower processing time compared to DWT. The paper details simulations conducted on both planar and space robots to analyze failures caused by disturbances in the joints.