This paper proposes a control system for the flexible material handling robot. In the past, there has been reported much research work on flexible material handling robot systems. In most of the previous work, control system parameters were treated as fixed. However, they often change due to variation of the flexible payloads. In some cases, control performance is degraded and the production process is terminated in some situations. To deal with these cases, we propose an error detection method and a replanning system. If system parameters change and control performance is degraded, this system detects error by itself and changes control parameters to recover from the error automatically. Some experimental examples are shown to confirm effectiveness of this proposed system.