Principles of legged locomotion have been established in the previous years. At present, many mathematical problems have been studied and solved; but in the implementation of this knowledge, new real problems have appeared. Flexion on links and joints and terrain compression introduce some undesirable characteristics in the system. These phenomena are not easy to model; therefore, sensors should be used. This paper deals with the implementation of attitude/altitude control on a walker. The main scope is to perform control using non-sophisticated sensors such as contact sensors, inclinometers, and joint position sensor. This paper describes the algorithms and the experimental results obtained working on a four legged walking machine. >