Power Assist H Control of Shift Lever with Spring Connected Link

Transcription

1 Extended Summary pp Power Assist H Control of Shift Lever with Spring Connected Link Mitsuo Hirata Member (Utsunomiya University) Tsutomu Ogiwara Non-member (Utsunomiya University) Hitoshi Okamoto Non-member (Utsunomiya University) Shuichi Adachi Member (Keio University) Kensuke Osamura Non-member (Calsonic Kansei Corporation) Shinya Kobayashi Non-member (Calsonic Kansei Corporation) Keywords: shift lever with spring connected link, power assist control, H control theory Many attempts have been made to locate the shift lever of the automatic transmission on the instrument panel in order to enlarge the vehicle interior space. If the length of the shift lever can be shorten, a better interior space will be provided. However, a short lever requires a larger force to move the shift lever, and the operational feeling is also degraded. To cope with this problem, the shift lever assisted by a DC motor has been developed for practical use. The power assist control system of the shift lever requires to detect the reaction force to the operator. In the conventional system, a magnetostrictive sensor is used as a force sensor. However the magnetostrictive sensor is sensitive to environmental change. Thus, it is difficult to use the sensor in vehicle. This paper proposes a shift lever with a spring connected link as shown in Fig.. The reaction force can be detected by measuring the displacement of the spring using an inexpensive sensor such as a potentiometer. The control objective is to generate an ideal reaction force when the operator changes the range of the transmission. Since the displacement of the spring is proportional to the reaction force, the control system can be configured to control the displacement of the spring as shown in Fig. 2. In Fig. 2, Reference RS generates an ideal reaction force which can be modeled as a function of the operation angle θ L. The feedback controller is designed by using the H control theory so as to have a good disturbance rejection and robust stability. Since the plant has a zero at the origin, the selection of the weighting function of the H design is discussed in the paper. Figure 3 shows the experimental result when the operator moves the shift lever from P(Parking) to R(Reverse) range. The solid line and the dashed one show the experimental result and the ideal trajectory generated by Reference FS in Fig. 2 respectively. From this figure, it is confirmed that the proposed control system achieves a good similarity with the ideal reaction force property. It is also confirmed that the proposed system not only reduces the operational force but also improves the operational feeling. Fig. 2. Block diagram of power assist control system Fig.. Schematic diagram of the plant model Fig. 3. Operation angle vs. reaction force 4

2 H Power Assist H Control of Shift Lever with Spring Connected Link Mitsuo Hirata, Member, Tsutomu Ogiwara, Non-member, Hitoshi Okamoto, Non-member, Shuichi Adachi, Member, Kensuke Osamura, Non-member, Shinya Kobayashi, Non-member We have developed the shift lever with a spring connected link. It can detect the reaction force to the operator by using inexpensive displacement sensors such as potentiometers. For this system, we propose a model-based power assist control method. The proposed control system is composed of a reference generator and a feedback controller. The reference generator is introduced to generate an ideal reaction force to the operator. The feedback controller is designed by H control theory to achieve disturbance attenuation. The effectiveness of the proposed method is shown by experiments. H Keywords: shift lever with spring connected link, power assist control, H control theory. Automatic Transmission AT () AT Utsunomiya University 7--2, Yoto, Utsunomiya Keio University 3-4-, Hiyoshi, Kohoku-ku, Yokohama Calsonic Kansei Corporation 7, Sakaecho, Sano AT (2) (3) (4) (5) H D

3 Table. Physical parameters. Fig.. Shift lever with a spring connected link. Annotation Symbol Unit Operation Force F O N Length of shift lever L s m Spring constant k Nm/rad Worm gear ratio N Transmission efficiency of worm gear η Inertia moment of shift lever J L kgm 2 Damping coefficient of shift lever D L Nms/rad Inertia moment of motor J M kgm 2 Damping coefficient of motor D M Nms/rad Applied voltage to motor V m V Inductance of armature circuit L H Wound resistor of armature circuit R Ω Torque constant K T Nm/A Back EMF constant K e Vs/rad Torque of shift lever T L Nm Torque of motor T m Nm Torque from check mechanism T c Nm Fig Schematic diagram of the plant model DC AT AT DC DC 2 θ L [rad] θ M [rad] θ r [rad] θ r := θ L θ M AT Parking P Reverse R 3 P R Fig. 3. Characteristics of check mechanism between P and R range. 3 θ M k cg (θ M )[Nm/deg] AT AT 2 2 DC kθ r /L s F 0 F 0 F 0 34 IEEJ Trans. IA, Vol.27, No., 2007

4 H 4 Fig. 4. Block diagram of the plant. θ r θ r 2 4 DC V m θ L θ r F O θ r P RO DC V m θ r P RM k cg (θ M ) k cg P RO P RM P RO k cg k cg k cg = (s ) P RO (s) = (s ) () (s s ) k cg = 2.08 P RO (s) = 9.44(s + 254)(s s ) (s + 255)(s s + 54) (2) (s s ) k cg = (s + 74.)(s 46.25) P RO (s) = (s )(s 40.32) (3) (s s ) k cg P RO P RO k cg = 0 k cg = 2.08 k cg = 2. Fig. 5. Frequency responses of P RO. P RO k cg P RM 3 k cg k cg = 0 P RM (s) = (s ) (s + 254)(s ) (s s ) (4) k cg = 2.08 P RM (s) = k cg = 2. P RM (s) = s(s ) (s + 255)(s s + 54) (s s ) (5) s(s ) (s + 254)(s )(s 40.32) (s s ) (6) k cg P RM 6 P RM P RM k cg = 0 θ r θ r θ r = θ L θ M = 0 kθ r 4 /(J L s + D L ) θ L θ M = θ L θ M k cg 0 D

5 7 Fig. 7. Block diagram of power assist control system. 6 P RM k cg = 0 k cg = 2.08 k cg = 2. Fig. 6. Frequency responses of P RM. 2 k cg = 0 P RM P RM θ r () θ M θ M 3 6 k cg P RM Reference FS θ r H AT P Parking R Reverse N Neutral D Drive P R 3 2 P R 8 Fig An ideal characteristic of reaction force θ θ 2 F F kθ r /L s k/l s θ r θr re f 8 θr re f 7 Reference FS 3 3 H H w( z( H (7) (8) H 3 3 F O θ r F 0 θ r 36 IEEJ Trans. IA, Vol.27, No., 2007

6 H S T S + T = w [z, z 2 ] T G z,2 w := P RO + P RM K W S P RO K + P RM K W T (7) 9 Fig. 9. Generalized plant. F O F O θ r 9 u y θ r H 7 y θr re f θ r H θ r re f = 0 w w z H θ r z 2 W S W T w 2 w 3 H ε ε 2 (7) H 2 2 P RM k cg k cg P RM P RM k cg (6) k cg (θ M ) k cg = W S W T W S = P RO W S, G z,2 w = W T = P RO P RM W T (8) + P RM K W S P RM K + P RM K W T =: S W S T W T (9) W S W T S T θ r 0 P RM k cg = 0 K(s) K(s) s = 0 S (0) = + P RM (0)K(0) = (0) k cg = W S W S (s) = 833.3s(s ) (s )(s ) () W T 42.9 ε 2 ε 3 W S W T w z z 2 H w 2 w 3 9 H 0 D

7 0 H Fig. 0. Frequency response of H controller. 2 θ L Fig. 2. Time response of operation angle θ L. S / W S Fig.. Frequency responses of S and / W S. 3 Fig. 3. Operation angle vs. reaction force. 727s(s + 254)(s ) K(s) = (s + 358)(s )(s ) (s s + 798) (s )(s s ) / W S Hz 0dB 0 3 Hz 0dB 0 4. H ms P R P R θ r 8 PID 7 H PID Reference FS 0 PID 38 IEEJ Trans. IA, Vol.27, No., 2007

8 H 4 PID Fig. 4. Operation angle vs. reaction force (PID control)..28 K PID (s) = s s s PID 4 0 N PID 5. H H K. Osamura, Y. Hirota, Y. Takagi, and R. Watanabe: Control System Models for Automatic Transmission Shift Assisting Devices, In Proc. of SICE 5th Annual Conference on Control Systems, pp (2005) (in Japanese), 5, pp (2005) 2 H. Kazerooni: Human-Robot Interaction via the Transfer of Power and Information Signals, IEEE Trans. on SMC, Vol.20, No.2, pp (990) 3 K. Kosuge, Y. Fujisawa, and T. Fukuda: Control of Mechanical System with Man-Machine Interaction,Proc.of IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, pp (992) 4 N. Sugitani, Y. Fujiwara, K. Uchida, and M. Fujita: Electric Power Steering with H Control Designed to Obtain Road Information, Proc. American Control Conference, Vol.5, pp (997) 5 Y. Yamada, H. Konosu, T. Morizono, and Y. Umetani: Proposal of Skill- Assist for Mounting Operations in Automobile Assembly Processes, Trans. of the Japan Society of Mechanical Engineers. C, Vol.68, No.666, pp (2002) (in Japanese), C, Vol.68, No.666, pp (2002) 6 K. Ohnishi: Robust Motion Control by Disturbance Observer, Journal of the Robotics Society of Japan, Vol., No.4, pp (993) (in Japanese),, Vol., No.4, pp (993) 7 H, (994) 8 MATLAB, (998) IEEE MATLAB D

9 IEEE IEEJ Trans. IA, Vol.27, No., 2007