In this master thesis a control strategy for a Human Power Amplifier (HPA) ispresented. An HPA can be described as a machine that amplifies a force exertedby a human operator. The HPA in this thesis can best be described as a mechanicalore with two degrees of freedom.The approach for the control strategy presented here is to look at the controlproblem not directly as a force amplifying problem, but as coordination problembetween the real system and a virtual system, where the virtual system is used asa reference. If the systems are synchronized then desired force amplification willnaturally follow from that.Furthermore is the possibility to implement guidance and obstacle avoidanceon the machine investigated. The guidance is performed by using velocity fields,i.e., vector fields where a vector represents the desired velocity for each point inthe plane. For the obstacle avoidance potential fields are used, where the idea isthat a high potential should repel the machine from restricted areas.