Steering control device

Abstract

To provide a steering control device capable of suppressing fluctuations in steering torque resulting from Cardan joint.SOLUTION: A PU 52 calculates the torque corresponding to a value obtained by multiplying a sum of a detection value Trq by a torque sensor 72 and a torque of an assist motor 42 by a coefficient changing with a steering angle. The PU 52 controls the torque of the assist motor 42 according to the calculated torque.SELECTED DRAWING: Figure 1

Claims

1. A steering control device that controls a steering device, The steering device comprises a steering wheel, an input shaft, an intermediate shaft, an output shaft, a first cardan joint, a second cardan joint, an assist motor, and a steering wheel. The input shaft is connected to the steering wheel, The first cardan joint is a member that connects the input shaft and the intermediate shaft, The second cardan joint is a member that connects the intermediate shaft and the output shaft, The steering torque input to the steering wheel is transmitted to the steering wheel via the input shaft, the intermediate shaft, and the output shaft. The assist motor is a motor that applies torque to a position closer to the steering wheel than the second cardan joint, It is configured to perform torque acquisition processing, steering angle variable acquisition processing, and assist control processing. The torque acquisition process is a process for acquiring the detected torque value applied at a position closer to the steering wheel than the second cardan joint. The steering angle variable acquisition process is a process of acquiring the value of a steering angle variable that indicates the steering angle, which is the angle of the steering wheel. The assist control process includes a variable torque control process that takes the value of the steering angle variable as input and varies the torque of the assist motor according to the steering angle. The variable torque control process includes a compensation torque control process that controls the torque of the assist motor according to a torque corresponding to a value obtained by multiplying the sum of the detected value and the torque of the assist motor by a coefficient. The coefficient is a steering control device, wherein the coefficient is the value obtained by subtracting from 1 the ratio of the torque applied at a position close to the steering wheel to the steering torque, which is the torque applied to the steering wheel.

2. A steering control device that controls a steering device, The steering device comprises a steering wheel, an input shaft, an intermediate shaft, an output shaft, a first cardan joint, a second cardan joint, an assist motor, and a steering wheel. The input shaft is connected to the steering wheel, The first cardan joint is a member that connects the input shaft and the intermediate shaft, The second cardan joint is a member that connects the intermediate shaft and the output shaft, The steering torque input to the steering wheel is transmitted to the steering wheel via the input shaft, the intermediate shaft, and the output shaft. The assist motor is a motor that applies torque to a position closer to the steering wheel than the second cardan joint, It is configured to perform torque acquisition processing, steering angle variable acquisition processing, and assist control processing. The torque acquisition process is a process for acquiring the detected torque value applied at a position closer to the steering wheel than the second cardan joint. The steering angle variable acquisition process is a process of acquiring the value of a steering angle variable that indicates the steering angle, which is the angle of the steering wheel. The assist control process includes a variable torque control process that takes the value of the steering angle variable as input and varies the torque of the assist motor according to the steering angle. The aforementioned fluctuating torque control process includes a steering torque-dependent process that controls the torque of the assist motor using the steering torque and coefficient determined from the detected value as input. The coefficient is a steering control device in which the coefficient is calculated based on the value of the steering angle variable as an input variable and is the ratio of the steering torque, which is the torque applied to the steering wheel, to the torque applied to a position close to the steering wheel.

3. A steering control device that controls a steering device, The steering device comprises a steering wheel, an input shaft, an intermediate shaft, an output shaft, a first cardan joint, a second cardan joint, an assist motor, and a steering wheel. The input shaft is connected to the steering wheel, The first cardan joint is a member that connects the input shaft and the intermediate shaft, The second cardan joint is a member that connects the intermediate shaft and the output shaft, The steering torque input to the steering wheel is transmitted to the steering wheel via the input shaft, the intermediate shaft, and the output shaft. The assist motor is a motor that applies torque to a position closer to the steering wheel than the second cardan joint, It is configured to perform torque acquisition processing, steering angle variable acquisition processing, and assist control processing. The torque acquisition process is a process for acquiring the detected torque value applied at a position closer to the steering wheel than the second cardan joint. The steering angle variable acquisition process is a process of acquiring the value of a steering angle variable that indicates the steering angle, which is the angle of the steering wheel. The assist control process includes a process that takes the detected value and coefficient as input and controls the torque of the assist motor in accordance with the steering torque determined from the detected value and coefficient, The coefficient is a steering control device in which the coefficient is calculated based on the value of the steering angle variable as an input variable and is the ratio of the steering torque, which is the torque applied to the steering wheel, to the torque applied to a position close to the steering wheel.

4. A steering control device that controls a steering device, The steering device comprises a steering wheel, an input shaft, an intermediate shaft, an output shaft, a first cardan joint, a second cardan joint, an assist motor, and a steering wheel. The input shaft is connected to the steering wheel, The first cardan joint is a member that connects the input shaft and the intermediate shaft, The second cardan joint is a member that connects the intermediate shaft and the output shaft, The steering torque input to the steering wheel is transmitted to the steering wheel via the input shaft, the intermediate shaft, and the output shaft. The assist motor is a motor that applies torque to a position closer to the steering wheel than the second cardan joint, It is configured to perform torque acquisition processing, steering angle variable acquisition processing, and assist control processing. The torque acquisition process is a process for acquiring the detected torque value applied at a position closer to the steering wheel than the second cardan joint. The steering angle variable acquisition process is a process of acquiring the value of a steering angle variable that indicates the steering angle, which is the angle of the steering wheel. The assist control process includes a variable torque control process that takes the value of the steering angle variable as input and varies the torque of the assist motor according to the steering angle. Equipped with a memory device that stores mapping data, The steering angle variable acquisition process is a process that acquires the value of a variable indicating the rotation angle of the output shaft as the value of the steering angle variable. The aforementioned mapping data is data that defines a mapping that takes the value of the steering angle variable as input and outputs the steering angle, The assist control process includes a steering angle calculation process that calculates the steering angle by inputting the value of the steering angle variable into the mapping, It is configured to perform steering angle acquisition and update processes, The steering angle acquisition process is a process for acquiring the steering angle, The steering control device includes a process for updating the mapping data using the steering angle acquired by the steering angle acquisition process and the value of the steering angle variable acquired by the steering angle variable acquisition process as input.

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