Electric power assisted steering apparatus and method of assisting

Abstract

The present application provides an electric power steering device and an assisting method thereof. A lane recognition unit recognizes lane information of a lane in which a vehicle travels. A steering information sensing unit senses steering information. An assisting control unit controls the electric power steering device to perform a steering assist operation in accordance with a steering assist amount constituted by the lane information and the steering information, and controls the electric power steering device to perform the steering assist operation in accordance with a learning steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be recognized.

Description

TECHNICAL FIELD

[0001] The present application relates to an assist device, in particular, to an electric power steering device and an assist method thereof. BACKGROUND

[0002] In recent years, in consideration of the weak in traffic participants, more and more active efforts are made to provide a people-friendly and sustainable transportation system. To achieve this goal, we are focusing on research and development to further improve traffic safety and convenience through research and development of driving assistance.

[0003] Due to the progress of technology and the demand for real-time information, there are now many devices that can assist users in driving, and therefore the functional needs of users for these assistive devices have increased. Generally, driving assist devices often rely on lane markings on the road surface to perform driving assistance. When a vehicle is driving on a sloping road surface or the vehicle is not balanced left and right, if the lane marking information cannot be sensed suddenly, the driving assistance cannot be performed, and therefore the vehicle's driving trajectory may deviate. In addition, the sudden removal of driving assistance will increase the steering load of the driver, and the sudden increase in the steering load of the driver is likely to lead to traffic accidents, so improvement of the driving assist device is a very important issue. SUMMARY

[0004] The present application provides an electric power steering device and an assist method thereof, which can continue to perform driving assistance when the reference for performing driving assistance outside the vehicle cannot be sensed, thereby effectively improving the safety of vehicle driving and contributing to the development of a sustainable transportation system.

[0005] The electric power steering device of the present application is used for a vehicle and performs a steering assist operation using an electric motor, and includes a lane recognition unit, a steering information sensing unit, and an assist control unit. The lane recognition unit recognizes lane information of a lane in which the vehicle is driving. The steering information sensing unit senses steering information. The assist control unit is coupled to the electric motor, the lane recognition unit, and the steering information sensing unit, controls the electric power steering device to perform the steering assist operation in accordance with a steering assist amount constituted by the lane information and the steering information, and controls the electric power steering device to perform the steering assist operation in accordance with a learning steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be recognized.

[0006] In an embodiment of the present application, the learning steering assist amount is an average value of the steering assist amount during the learning period.

[0007] In an embodiment of the present application, the assist control unit determines whether the lane in which the vehicle is driving is a straight lane in accordance with the lane information and the steering information, and the lane in which the vehicle is driving is a straight lane during the learning period.

[0008] In one embodiment of the present application, the above-mentioned assist control unit gradually changes the steering assist amount to the learned steering assist amount during the transition period.

[0009] In one embodiment of the present application, the above-mentioned assist control unit changes the control of the electric power steering device from the learned steering assist amount to the steering assist amount determined from the lane information and the steering information when the lane information is re-identified.

[0010] In one embodiment of the present application, the above-mentioned assist control unit gradually changes the learned steering assist amount to the steering assist amount determined from the lane information and the steering information during the transition period.

[0011] The present application also provides an assist method for an electric power steering device for a vehicle and using an electric motor to perform a steering assist operation, the assist method for the electric power steering device including the steps of: identifying lane information of a lane in which the vehicle is traveling; sensing steering information; controlling the electric power steering device to perform the steering assist operation in accordance with a steering assist amount determined from the lane information and the steering information; and controlling the electric power steering device to perform the steering assist operation in accordance with a learned steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be identified.

[0012] In one embodiment of the present application, the above-mentioned learned steering assist amount is an average of the steering assist amounts during the learning period.

[0013] In one embodiment of the present application, the above-mentioned assist method for the electric power steering device includes determining whether the lane in which the vehicle is traveling is a straight lane in accordance with the lane information and the steering information, wherein the lane in which the vehicle is traveling is a straight lane during the learning period.

[0014] In one embodiment of the present application, the above-mentioned assist method for the electric power steering device includes gradually changing the steering assist amount to the learned steering assist amount during the transition period.

[0015] In one embodiment of the present application, the above-mentioned assist method for the electric power steering device includes changing the control of the electric power steering device from the learned steering assist amount to the steering assist amount determined from the lane information and the steering information when the lane information is re-identified.

[0016] In one embodiment of the present application, the learned steering assist amount is gradually changed to the steering assist amount determined from the lane information and the steering information during the transition period.

[0017] Based on the above, when the lane information cannot be recognized, the electric power steering device is controlled to perform the steering assist operation according to the learning steering assist amount constituted by the steering assist amount during the learning period. Thus, when the lane information cannot be recognized, the electric power steering device is controlled to perform the steering assist operation using the learning steering assist amount, so that the steering load of the driver can be prevented from suddenly increasing due to the sudden disappearance of the steering assist of the vehicle, and thus the stability of the vehicle during travel can be effectively improved, and the safety of the vehicle during driving can be improved.

[0018] In order to make the above features and advantages of the present application more apparent, specific embodiments are described below in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic diagram of an electric power steering device for a vehicle according to an embodiment of the present application.

[0020] Figure 2 is a schematic diagram of a steering assist operation of a vehicle according to an embodiment of the present application.

[0021] Figure 3 is a schematic diagram of a vehicle traveling on an inclined lane according to an embodiment of the present application.

[0022] Figure 4 is a schematic diagram of a learning steering assist amount according to another embodiment of the present application.

[0023] Figure 5 is a schematic diagram of adjustment of a steering assist amount according to an embodiment of the present application.

[0024] Figure 6 is a flowchart of an assist method of an electric power steering device for a vehicle according to an embodiment of the present application.

[0025] Figure 7 is a flowchart of an assist method of an electric power steering device for a vehicle according to another embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the content of the present application more easily understood, specific embodiments are described below as examples in which the present application can be embodied. In addition, wherever possible, the same reference numerals are used for components / elements in the drawings and embodiments to represent the same or similar components.

[0027] Figure 1 is a schematic diagram of an electric power steering device for a vehicle according to an embodiment of the present application, please refer to Figure 1The electric power steering apparatus can include an electric motor 102, an assist control unit 104, a lane recognition unit 106, and a steering information sensing unit 108, and the assist control unit 104 is coupled to the electric motor 102, the lane recognition unit 106, and the steering information sensing unit 108. The assist control unit 104 can be, for example, a processor, and the lane recognition unit 106 can include, for example, at least one of a camera, a radar, and a global positioning system. The steering information sensing unit 108 can be, for example, a torque sensor. The embodiments of the assist control unit 104, the lane recognition unit 106, and the steering information sensing unit 108 of the present embodiment are merely exemplary embodiments, and the present embodiment is not limited to the embodiments.

[0028] The lane recognition unit 106 can recognize lane information of a lane in which the vehicle is traveling. For example, the lane recognition unit 106 can recognize that the lane in which the vehicle is traveling is a straight lane or a curved lane by recognizing road markings or traffic signs on the lane, and provide the lane information according to the recognition result. In some embodiments, the lane information can include curvature information of the lane, but is not limited thereto. The steering information sensing unit 108 can sense at least one of a steering torque, a steering speed, and a steering angle of the driver operating the steering wheel of the vehicle, and obtain steering information.

[0029] When the lane recognition unit 106 is able to recognize the lane, the assist control unit 104 can control the electric power steering apparatus to perform a steering assist operation according to a steering assist amount of the vehicle constituted by the lane information provided by the lane recognition unit 106 and the steering information provided by the steering information sensing unit 108, to reduce the driving load of the driver. When the lane recognition unit 106 is able to recognize the lane, the assist control unit 104 can further calculate a learning steering assist amount according to the steering assist amount during a learning period, and when the lane recognition unit 106 is unable to recognize the lane, the assist control unit 104 can control the electric power steering apparatus to perform a steering assist operation according to the learning steering assist amount constituted by the steering assist amount during the learning period, to avoid sudden increase in the steering load of the driver due to sudden disappearance of the steering assist of the vehicle, thereby improving the safety of driving the vehicle. For example, assuming that the lane recognition unit 106 generates the lane information by recognizing markings on the lane, when the vehicle travels onto a lane on which no markings are drawn, the lane recognition unit 106 will be unable to recognize the lane information and provide the lane information due to disappearance of the markings, and the assist control unit 104 can then control the electric motor 102 to perform a steering assist operation according to the learning steering assist amount constituted by the steering assist amount during the learning period.

[0030] Further, the steering assist operation of the vehicle can be as shown in Figure 2 Figure 2 ​In this embodiment, the vehicle enters the straight lane from the curved lane and then enters the curved lane from the straight lane. In this embodiment, the vehicle... Figure 3 As shown, the vehicle is traveling on the sloping road R1, which causes the vehicle to have a directional... Figure 3 The tendency of the arrow to deviate, as shown, allows the driver to more easily maintain the vehicle's straight-line driving along a straight lane by providing steering assistance through the auxiliary control unit 104. The auxiliary control unit 104 can determine whether the vehicle is traveling in a straight lane, for example, based on the lane curvature information provided by the lane recognition unit 106. In this embodiment, the auxiliary control unit 104 determines whether the vehicle is traveling in a straight lane based on the reciprocal of the lane curvature, but this is not a limitation. Specifically, when the reciprocal of the lane curvature is less than a default value, it can be determined that the vehicle is traveling in a straight lane, such as in... Figure 2 In the embodiment, it can be determined that the vehicle is traveling in a straight lane after time point t1 and before time point t5.

[0031] Furthermore, the auxiliary control unit 104 can also determine whether the vehicle is traveling in a straight lane based on the steering signal provided by the steering information sensing unit, wherein the steering signal may include, for example, at least one of steering torque and steering angle. Compared to when the vehicle is traveling in a straight lane, the steering wheel has a larger steering torque and steering angle when the vehicle is traveling in a curve; therefore, by comparing the steering signal value with a threshold, it can be determined whether the vehicle is traveling in a straight lane. For example, in Figure 2 In this embodiment, it can be determined whether a vehicle is traveling in a straight lane by comparing whether the steering signal value (e.g., the steering torque or steering angle) is greater than a threshold TH. When the steering signal value is greater than the threshold TH (e.g., before time point t0 and after time point t6), it can be determined that the vehicle is traveling in a curved lane. Conversely, when the steering signal value is less than the threshold TH (e.g., after time point t0 and before time point t6), it can be determined that the vehicle is traveling in a straight lane. Figure 2 In the embodiment, at time points t1 and t5, it can be determined that the vehicle is traveling in a straight lane.

[0032] To ensure accurate determination that the vehicle is traveling in a straight lane, the auxiliary control unit 104 can simultaneously determine whether the vehicle is traveling in a straight lane based on both lane curvature and steering signals. That is, the vehicle is only determined to be traveling in a straight lane when both methods indicate it is. Figure 2 As shown in the embodiment, the auxiliary control unit 104 can determine that the vehicle is traveling in a straight lane between time points t1 and t6.

[0033] When the assist control unit 104 determines that the vehicle is running on a straight lane and the lane recognition unit 106 can still recognize the lane on which the vehicle is running and provide the lane information, the assist control unit 104 calculates a learning steering assist amount according to the steering assist amount during the learning period while determining a steering assist amount (e.g., an assist torque of the steering wheel) according to the lane information and the steering information. For example, the assist control unit 104 can calculate the learning steering assist amount according to the steering assist amount during a learning period T1 starting at time point t1. The learning period T1 can be, for example, a period of x seconds as shown in FIG. 6. Assuming that the current time point is t1+x, the assist control unit 104 can calculate the learning steering assist amount according to the steering assist amount during the period from time point t1 to t1+x. For example, the assist control unit 104 can sample the steering assist amount at a fixed frequency and calculate the average of the sampled steering assist amounts during the learning period T1 as the learning steering assist amount. The learning steering assist amount can be updated continuously over time. For example, the learning steering assist amount at time point tn+x can be the average of the steering assist amounts sampled during the period from time point tn to tn+x, where n and x are positive integers. The length of the learning period T1 can be determined, for example, according to the reciprocal of the sampling frequency of the steering assist amount. For example, the length of the learning period T1 can be twice the reciprocal of the sampling frequency of the steering assist amount. The sampling frequency of the steering assist amount can be designed to be a frequency that does not cause the driver to feel uncomfortable. Figure 2 In the embodiment, the assist control unit 104 can start calculating the learning steering assist amount according to the steering assist amount during the learning period T1 at time point t1. For example, the assist control unit 104 can calculate the learning steering assist amount according to the steering assist amount during a recent period of time. Further, the learning period T1 can be, for example, a period of x seconds as shown in FIG. 6. Assuming that the current time point is t1+x, the assist control unit 104 can calculate the learning steering assist amount according to the steering assist amount during the period from time point t1 to t1+x. For example, the assist control unit 104 can sample the steering assist amount at a fixed frequency and calculate the average of the sampled steering assist amounts during the learning period T1 as the learning steering assist amount. The learning steering assist amount can be updated continuously over time. For example, the learning steering assist amount at time point tn+x can be the average of the steering assist amounts sampled during the period from time point tn to tn+x, where n and x are positive integers. The length of the learning period T1 can be determined, for example, according to the reciprocal of the sampling frequency of the steering assist amount. For example, the length of the learning period T1 can be twice the reciprocal of the sampling frequency of the steering assist amount. The sampling frequency of the steering assist amount can be designed to be a frequency that does not cause the driver to feel uncomfortable. Figure 4

[0034] In the embodiment, when the lane recognition unit 106 cannot recognize the lane and cannot provide the lane information at time point t2, the assist control unit 104 can control the electric motor 102 to perform the steering assist operation according to the learning steering assist amount corresponding to the time point t2. Further, the assist control unit 104 can gradually change the steering assist amount to the learning steering assist amount during a transition period T2 to further avoid a sudden increase in the load on the steering of the driver. For example, as shown in FIG. 6, the assist control unit 104 can gradually change the steering assist amount to the learning steering assist amount during the transition period T2. Figure 2 Figure 5 ​​As shown, the assist control unit 104 can calculate a final steering assist amount in accordance with the steering assist amount Ql determined by the lane information and the steering information at the time point t2 and the learned steering assist amount Q2 calculated at the time point t2 during the transition period T2, and control the electric motor 102 to perform the steering assist operation in accordance with the final steering assist amount. For example, the final steering assist amount at each time point during the transition period T2 can be equal to the sum of the corresponding steering assist amount Ql and the learned steering assist amount Q2, and as time elapses, the proportion of the steering assist amount Ql in the final steering assist amount decreases and the learned steering assist amount Q2 increases, and at the end of the transition period T2 (i.e., the time point t3) in this embodiment, the final steering assist amount is equal to the learned steering assist amount Q2, but the application is not limited thereto.

[0035] Similarly, when the lane recognition unit 106 can recognize the lane again when the marking line Ll appears again, the assist control unit 104 can gradually change the learned steering assist amount to the steering assist amount composed of the lane information and the steering information during the transition period T3, and the change manner can be similar to that of the transition period Tl, for example. Figure 5 The embodiments of the embodiments are not described here. It is worth noting that in this embodiment, since the vehicle continues to travel in the straight lane, the learned steering assist amount can be continuously used for the steering assist operation, and there is no need to set the transition period T3 at the time point t4 when the marking line Ll appears, but can enter the transition period T3 (time points t6-t7) when the vehicle travels to the curved lane, but in other embodiments, the starting position of the transition period T3 can also be set at the time point t4 when the marking line Ll appears. It is worth noting that the above-mentioned embodiments are used to illustrate the steering assist of the vehicle when the vehicle travels in the straight lane, but the application is not limited thereto, and in other embodiments, the steering assist of the vehicle can also be performed in the same way in the curved lane.

[0036] As described in the above embodiments, the assist method for the electric power steering device of the vehicle can be, for example Figure 6The lane information and the steering information are then used to determine the steering assist amount. As shown in FIG. 6, first, it is determined whether the vehicle is traveling on a straight lane based on the lane information (step S602). For example, it can be determined whether the vehicle is traveling on a straight lane based on the inverse of the lane curvature. When the inverse of the lane curvature is less than a default value, it can be determined that the vehicle is traveling on a straight lane. If it is determined that the vehicle is traveling on a straight lane, it is then determined whether the steering signal is less than a default value (step S604). For example, it can be determined whether the steering torque of the steering wheel is less than a threshold value. When the steering torque of the steering wheel is less than the threshold value, it can be determined that the vehicle is traveling on a straight lane. After it is determined that the vehicle is traveling on a straight lane through steps S602 and S604, the learning steering assist amount is calculated and updated based on the steering assist amount during the learning period while the steering assist amount is determined based on the lane information and the steering information (step S606). It is then determined whether the lane can be recognized (step S608). If the lane can still be recognized, the learning steering assist amount is continuously calculated and updated (step S606). If the lane cannot be recognized, the adjustment of the steering assist amount is performed (step S610). For example, the final steering assist amount during the transition period T2 is calculated to perform the steering assist operation based on the final steering assist amount. It is then determined whether the steering signal is greater than or equal to a default value (step S612). For example, it is determined whether the steering torque of the steering wheel is greater than or equal to a threshold value. When the steering torque of the steering wheel is greater than or equal to the threshold value, it can be determined that the vehicle is traveling on a curved lane. The adjustment of the steering assist amount is then performed (step S614). For example, the adjustment of the steering assist amount during the transition period T3 is performed. That is, the learning steering assist amount is gradually changed to the steering assist amount determined based on the lane information and the steering information during the transition period by the assist control unit 104. In addition, after the vehicle enters the curved lane, the learning steering assist amount is calculated based on the steering assist amount during the learning period by the assist control unit 104 as described in the above embodiment to control the electric motor 102 to perform the steering assist operation based on the learning steering assist amount when the lane recognition unit 106 cannot recognize the lane. Since the learning steering assist amount is continuously updated, the learning steering assist amount calculated by the assist control unit 104 when the vehicle is traveling on the curved lane will overwrite the learning steering assist amount calculated when the vehicle was traveling on the straight lane.

[0037] Figure 7is a flowchart of an assisting method of an electric power assisted steering apparatus for a vehicle according to another embodiment of the present application. As known from the above embodiment, the assisting method of the electric power assisted steering apparatus can include at least the following steps. First, lane information of a lane in which the vehicle is traveling is identified (step S702), which can include, but is not limited to, curvature information of the lane. Next, steering information is sensed (step 704), which can include, but is not limited to, at least one of steering torque, steering speed and steering angle. Then, the electric power assisted steering apparatus is controlled to perform a steering assist operation according to a steering assist amount constituted by the lane information and the steering information (step S706). Thereafter, when the lane information cannot be identified, the electric power assisted steering apparatus is controlled to perform the steering assist operation according to a learning steering assist amount constituted by the steering assist amount during a learning period (step S708), which can be, for example, an average of the steering assist amount during the learning period, but is not limited thereto. Furthermore, the steering assist amount can be gradually shifted to the learning steering assist amount during a transition period, for example, a ratio of the steering assist amount to the learning steering assist amount can be adjusted over time, and a sum of the steering assist amount and the learning steering assist amount can be used as a final steering assist amount, according to which the electric power assisted steering apparatus is controlled to perform the steering assist operation.

[0038] Furthermore, the above embodiment illustrates the steering assist of the vehicle when the vehicle is traveling in a straight lane, but is not limited thereto. In other embodiments, the steering assist of the vehicle can be performed in the same manner when the vehicle is traveling in a curved lane, i.e., during a turn of the vehicle, for example, the learning steering assist amount can be used to control the electric power assisted steering apparatus to perform the steering assist operation when the lane information cannot be identified, and a transition period can be provided to avoid a sudden increase in the steering load of the driver, etc. Since the manner of controlling the electric power assisted steering apparatus to perform the steering assist operation when the vehicle is traveling in a curved lane is similar to the manner of controlling the electric power assisted steering apparatus to perform the steering assist operation when the vehicle is traveling in a straight lane in the above embodiment, those skilled in the art should be able to infer the implementation of the steering assist of the vehicle when the vehicle is traveling in a curved lane from the above embodiment, and thus will not be described again here.

[0039] In summary, the embodiments of the present application control the electric power assisted steering apparatus to perform the steering assist operation according to the learning steering assist amount constituted by the steering assist amount during the learning period when the lane information cannot be identified. Thus, the learning steering assist amount is used to control the electric power assisted steering apparatus to perform the steering assist operation when the lane information cannot be identified, which can avoid a sudden disappearance of the steering assist of the vehicle and a sudden increase in the steering load of the driver, and thus can effectively improve the safety of the vehicle driving.

[0040] Although the present application has been disclosed in the above embodiments, it is not intended to limit the present application, any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present application, therefore the scope of protection of the present application is defined by the claims.

Claims

1. An electric power steering apparatus for a vehicle that performs a steering assist operation using an electric motor, characterized by, The present application provides a lane recognition system for a vehicle, comprising: a lane recognition unit for recognizing lane information of a lane in which the vehicle is traveling; a steering information sensing unit for sensing steering information; and an assist control unit coupled to the electric motor, the lane recognition unit and the steering information sensing unit, for controlling the electric power steering device to perform a steering assist operation in accordance with a steering assist amount constituted by the lane information and the steering information, and for controlling the electric power steering device to perform the steering assist operation in accordance with a learning steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be recognized, the assist control unit determining whether the lane in which the vehicle is traveling is a straight lane in accordance with the lane information and the steering information, wherein the lane in which the vehicle is traveling is a straight lane during the learning period, the learning period starting when the vehicle is detected to be traveling on a straight lane, the assist control unit calculating the learning steering assist amount during the learning period when the assist control unit determines that the lane in which the vehicle is traveling is a straight lane, and the assist control unit controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount calculated during the learning period when the vehicle is traveling on a straight lane and the lane information cannot be recognized. The learning steering assist amount is an average of the steering assist amount during the learning period.

2. The electric power assisted steering apparatus of claim 1, wherein The assist control unit gradually changes the steering assist amount to the learning steering assist amount during a transition period.

3. The electric power assisted steering apparatus of claim 1, wherein The assist control unit switches from controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount to controlling the electric power steering device to perform the steering assist operation in accordance with the steering assist amount determined by the lane information and the steering information when the lane information is re-recognized.

4. The electric power steering apparatus according to claim 1, characterized by The assist control unit gradually changes the learning steering assist amount to the steering assist amount determined by the lane information and the steering information during a transition period.

5. The electric power assisted steering apparatus of claim 4, wherein The present application provides a lane recognition system for a vehicle, comprising:

6. An assist method for an electric power steering apparatus that is used for a vehicle and performs a steering assist operation using an electric motor, characterized by, a lane recognition unit for recognizing lane information of a lane in which the vehicle is traveling; a steering information sensing unit for sensing steering information; and an assist control unit coupled to the electric motor, the lane recognition unit and the steering information sensing unit, for controlling the electric power steering device to perform a steering assist operation in accordance with a steering assist amount constituted by the lane information and the steering information, and for controlling the electric power steering device to perform the steering assist operation in accordance with a learning steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be recognized, the assist control unit determining whether the lane in which the vehicle is traveling is a straight lane in accordance with the lane information and the steering information, wherein the lane in which the vehicle is traveling is a straight lane during the learning period, the learning period starting when the vehicle is detected to be traveling on a straight lane, the assist control unit calculating the learning steering assist amount during the learning period when the assist control unit determines that the lane in which the vehicle is traveling is a straight lane, and the assist control unit controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount calculated during the learning period when the vehicle is traveling on a straight lane and the lane information cannot be recognized. The learning steering assist amount is an average of the steering assist amount during the learning period. The assist control unit gradually changes the steering assist amount to the learning steering assist amount during a transition period. The assist control unit switches from controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount to controlling the electric power steering device to perform the steering assist operation in accordance with the steering assist amount determined by the lane information and the steering information when the lane information is re-recognized. The assist control unit gradually changes the learning steering assist amount to the steering assist amount determined by the lane information and the steering information during a transition period. The present application provides a lane recognition system for a vehicle, comprising: a lane recognition unit for recognizing lane information of a lane in which the vehicle is traveling; a steering information sensing unit for sensing steering information; and an assist control unit coupled to the electric motor, the lane recognition unit and the steering information sensing unit, for controlling the electric power steering device to perform a steering assist operation in accordance with a steering assist amount constituted by the lane information and the steering information, and for controlling the electric power steering device to perform the steering assist operation in accordance with a learning steering assist amount constituted by the steering assist amount during a learning period when the lane information cannot be recognized, the assist control unit determining whether the lane in which the vehicle is traveling is a straight lane in accordance with the lane information and the steering information, wherein the lane in which the vehicle is traveling is a straight lane during the learning period, the learning period starting when the vehicle is detected to be traveling on a straight lane, the assist control unit calculating the learning steering assist amount during the learning period when the assist control unit determines that the lane in which the vehicle is traveling is a straight lane, and the assist control unit controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount calculated during the learning period when the vehicle is traveling on a straight lane and the lane information cannot be recognized. The learning steering assist amount is an average of the steering assist amount during the learning period. The assist control unit gradually changes the steering assist amount to the learning steering assist amount during a transition period. The assist control unit switches from controlling the electric power steering device to perform the steering assist operation in accordance with the learning steering assist amount to controlling the electric power steering device to perform the steering assist operation in accordance with the steering assist amount determined by the lane information and the steering information when the lane information is re-recognized. The assist control unit gradually changes the learning steering assist amount to the steering assist amount determined by the lane information and the steering information during a transition period.

7. The assist method of the electric power assisted steering apparatus according to claim 6, characterized by, The learning steering assist amount is an average value of the steering assist amounts during the learning.

8. The electric power assisted steering apparatus assist method according to claim 6, characterized by, Comprises: Gradually changing the steering assist amount to the learning steering assist amount during a transition period.

9. The electric power steering apparatus auxiliary method according to claim 6, characterized by, Comprises: Upon re-recognizing the lane information, switching from controlling the electric power steering device in accordance with the learning steering assist amount to controlling the electric power steering device in accordance with the steering assist amount determined from the lane information and the steering information.

10. The electric power steering apparatus auxiliary method according to claim 9, characterized by, Gradually changing the learning steering assist amount to the steering assist amount determined from the lane information and the steering information during a transition period.

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