An assembling system comprising an assembling apparatus and a positioning device such as an industrial robot having an end portion which comprises a connector, the assembling apparatus comprising: a support structure assembly such as a frame structure which is provided with a coupling portion for coupling the support structure assembly to the positioning device such as an industrial robot, and a plurality of fixing members capable of fixing a workpiece, wherein each fixing member is connected with the support structure assembly via a linear actuator a first end of which being mounted on the support structure assembly and a second end of which carrying the fixing member, wherein the linear actuator is adapted to be controlled such that the distance between the first and the second end (29, 31) may be adjusted by a linear movement, wherein the positioning device is adapted to move the end portion relative to the position of a base of the positioning device and to position a workpiece in relation to another workpiece, so as to form an overall workpiece, wherein the coupling portion of the assembling apparatus is coupled with the connector, wherein the assembling system further comprises detection means which are adapted for determining the positions in space of a plurality of points on a workpiece, and wherein a control unit is provided adapted to control the adjustment of the distance between the first and the second end (29, 31) of one or more of said linear actuators in dependence of the positions as determined by the detection means, characterized in that in order to control the shape of a workpiece fixed by the fixing members the control unit is adapted to control the adjustment of the distance between the first and the second end (29, 31) of the linear actuators by controlling a drive of the linear actuators in dependence of the actual shape of the workpiece detected by the detection means. a support structure assembly such as a frame structure which is provided with a coupling portion for coupling the support structure assembly to the positioning device such as an industrial robot, and a plurality of fixing members capable of fixing a workpiece, wherein each fixing member is connected with the support structure assembly via a linear actuator a first end of which being mounted on the support structure assembly and a second end of which carrying the fixing member, wherein the linear actuator is adapted to be controlled such that the distance between the first and the second end (29, 31) may be adjusted by a linear movement, wherein the positioning device is adapted to move the end portion relative to the position of a base of the positioning device and to position a workpiece in relation to another workpiece, so as to form an overall workpiece, wherein the coupling portion of the assembling apparatus is coupled with the connector, wherein the assembling system further comprises detection means which are adapted for determining the positions in space of a plurality of points on a workpiece, and wherein a control unit is provided adapted to control the adjustment of the distance between the first and the second end (29, 31) of one or more of said linear actuators in dependence of the positions as determined by the detection means, characterized in that in order to control the shape of a workpiece fixed by the fixing members the control unit is adapted to control the adjustment of the distance between the first and the second end (29, 31) of the linear actuators by controlling a drive of the linear actuators in dependence of the actual shape of the workpiece detected by the detection means.