Abstract Dry dual clutch transmission (DCT) has played an important role in the high performance applications as well as low-cost market sectors in Asia, with a potential as the future mainstream transmission technology due to its high mechanical efficiency and driving comfort. Control system simplification and cost reduction has been critical in making dry DCT more competitive against other transmission technologies. Specifically, DCT clutch actuation system is a key component with a great potential for cost-saving as well as performance improvement. In this paper, a new motor driven clutch actuator with a force-aid lever has been proposed. A spring is added to assist clutch apply that can effectively reduce the motor size and energy consumption. The goal of this paper is to investigate the feasibility of this new clutch actuator, and the force-aid lever actuator's principle, physical structure design, and validation results are discussed in details. A prototyping of the proposed system is developed for the engagement of the clutch with a position-tracking controller. The advantages of the design and the performance of the control system developed are demonstrated through bench testing. It can be a promising low-cost clutch actuation system for a DCT transmission Introduction A dual clutch transmission (DCT) offers the driving comfort comparable to an automatic transmission, but with an efficiency similar to a manual transmission [ 1, 2, 3]. Due to these advantages, DCT has continued to be an important sector in the marketplace, with a potential to be the mainstream transmission technology in the future. The actuation system is a key control component of the DCT and has a potential for cost-saving and performance improvement. Compared to a conventional hydraulic actuation system, an electromechanical system has many merits, including the energy-efficiency, control precision and robustness [4, 5, 6]. However, the torque/force ratio it offers is lower than that from a hydraulic system. As a consequence, the size required makes an electromechanical actuator difficult to be packaged. In the effort of reducing the size, various force-aid mechanisms have been designed to reduce the torque/force ratio. It is desired for a DCT actuation system to output a large force with a small-force actuator. A self-energizing mechanism was introduced in the AMT clutch actuation system to amplify the normal force applied for the clutch engagement. It allows the clutch module to consume less amount of energy [7]. A wedge clutch proposed for an automatic transmission also uses the “self-reinforcement” feature to reduce the size of the motor used to actuate the system [ 8]. A lever based actuation system with a moving pivot has been designed to achieve a fast response and good performance with a 170w and 110w motor respectively in a 6-speed dry-DCT [9]. In this system, the force to engage a clutch comes from a preload spring, and the motor changes the force by tuning the lever ratio. In this paper, we propose a new actuation system that potentially has less power consumption than existing systems. The main components of the system include a motor, lever and pre-loaded spring. The spring can store and release energy. Both the motor and spring contribute to the clutch normal force through a lever with a fixed pivot. With the force-aid spring, it can be demonstrated that the whole system consumes less energy so that the motor size can be reduced compared to similar systems. Through the analysis and experimental study, we can demonstrate that a 50W motor is sufficient to achieve a similar performance compared to the system with a 110W (or 170W) motor discussed in [ 9]. In this paper, we present the design, analysis and validation of the new DCT clutch actuation system. In Section 1 , the principle of force-aid lever and the design are presented. In Section 2 , the dynamic model of the actuation system is establ