Jtekt Corporation

Hidenori Itamoto

Terutaka Tamaizumi

Shingo Maeda

Naoki Yamano

Gempei Nakasone

Toshie Hibi

Takashi Kageyama

Yoshihiro Yamashita

Takashi Kodera

Hirozumi Eki

Koji Anraku

Shunsuke Tsujii

Akihiro Tomita

Shingo Nitta

Hiromasa Tamaki

Xin Zhou

Akira Ito

Takashi Mitsuhara

Makoto Ikeno

Yufeng Lin

A motor control device includes a manual steering command value generation unit that generates a manual steering command value, and a hands-on/off determination unit that determines whether a driver is in a gripping state in which the driver is gripping a steering wheel or in a released state in which the driver is not gripping the steering wheel. The manual steering command value generation unit is configured to generate the manual steering command value based on an equation of motion. The motor control device further includes a coefficient value changing unit that changes a value of at least one coefficient among coefficients included in the equation of motion based on a determination result from the hands-on/off determination unit.

Motor control device

A manual steering command value calculation unit is configured to use road information including information on a road reaction torque to calculate a manual steering command value when a first condition that at least one of input torques for which a dead zone processing unit is provided is outside a dead zone range is satisfied, and not to use the road information to calculate the manual steering command value when the first condition is not satisfied. When alert vibration torque is being applied, the manual steering command value calculation unit uses the road information to calculate the manual steering command value for a predetermined period from a time when a state in which the first condition is satisfied changes to a state in which the first condition is not satisfied.

A steering computing device for calculating state quantity of a steering apparatus includes a processor. The processor is configured to execute a steering angle variable acquisition process, an output shaft angle variable acquisition process, and a joint angle variable calculation process. The steering angle variable acquisition process is a process of acquiring a value of a steering angle variable. The output shaft angle variable acquisition process is a process of acquiring a value of an output shaft angle variable as a variable indicative of a rotation angle of an output shaft of the steering apparatus. The joint angle variable calculation process is a process of calculating a value of the joint angle variable. The joint angle variable is a variable defining an angle formed between an axial direction of an input shaft of the steering apparatus and an axial direction of the output shaft.

Steering computing device

Provided is a steering control unit for improving influence of fluctuations in an estimated electrical angle on steering feel. A steering control unit includes a microcomputer that performs sensorless control of the driving of a motor by using an estimated electrical angle estimated by calculation. The microcomputer calculates the estimated electrical angle from a value that is obtained by selectively accumulating a first additional angle or a second additional angle. The microcomputer adjusts a vibration component of fluctuations in the estimated electrical angle by varying the amount of change in the first additional angle and the second additional angle.

Steering control unit

The steer-by-wire steering system comprise a steering input device and a steering operation device that steers wheels which are mechanically coupleable. The steering input device includes a steering-side motor that supplies a steering shaft with a steering reaction force, the steering operation device includes a steered-side motor that supplies a rack shaft with a steering force, and a power supply control circuit that controls the steering-side motor to generate the steering reaction force and that controls the steered-side motor to generate the steering force. When the duty ratio of a duty signal that is generated to control the power supply to the steered-side motor reaches a setting value that is defined to indicate that a steered angle becomes unable to follow a steering angle, the power supply control circuit controls the power supply to the steering-side motor such that the steering-side motor increases the steering reaction force.

Steer-by-wire steering system

Provided is a steering control apparatus in which the response of steering assistance to driver's steering can be improved during execution of rotation angle sensor-less control. When the rotation angle sensor-less control is executed and when an induced voltage value is equal to or lower than a threshold voltage, driving of a motor is controlled based on a second addition angle. The second addition angle is calculated such that values obtained by multiplying a first pre-addition angle calculated based on a steering torque and a second pre-addition angle calculated based on an induced voltage derivative by respective predetermined use ratios that are based on the induced voltage value are added together. By using the second addition angle, a more appropriate estimated electrical angle is calculated in response to a driver's steering situation.

Steering control apparatus

Provided is a steering control apparatus capable of executing driving assistance control even during rotation angle sensor-less control. When an induced voltage generated in a motor is equal to or lower than a threshold voltage at an early stage of execution of the rotation angle sensor-less control and when the driving assistance control is executed based on a command value from a higher-level control apparatus, a second pre-addition angle that is based on the command value is used as a second addition angle in place of a first pre-addition angle that is based on a steering torque. Therefore, even in a situation in which the steering torque is not detected due to, for example, execution of driving assistance, an estimated electrical angle of the motor is calculated by integrating the second addition angle. Then, driving of the motor is controlled based on the calculated estimated electrical angle.

A current command value calculation circuit includes an end abutment determination circuit and a guard processing circuit. When a decrease amount of an induced voltage value within a predetermined time is equal to or larger than a predetermined decrease amount in the state that a steering torque is equal to or larger than a predetermined torque, the end abutment determination circuit determines that the end abutment occurs. When a determination signal indicating that the end abutment state does not occur is input, the guard processing circuit outputs an elemental current command value directly as a q-axis current command value. When a determination signal indicating that the end abutment state occurs is input, the guard processing circuit outputs, as the q-axis current command value, a value obtained by limiting the elemental current command value so that its absolute value is equal to or lower than a predetermined limit current value.

A base current command value is calculated based on a steering torque and a vehicle speed. A desired steering angle value is a constant representing the virtual steering limit position. When a steering angle threshold is set to a value close to, and smaller than, the desired steering angle value, a first correction value is calculated so that a steering reaction force is increased rapidly when a steering angle becomes equal to or larger than the steering angle threshold. A second correction value is calculated so that the steering angle becomes equal to the desired steering angle value when the steering angle becomes equal to or larger than the steering angle threshold. The base current command value is corrected by the first correction value and the second correction value. The driver is thus restrained from turning the steering wheel to a position beyond the desired steering angle value.

Steering device

There is provided a steering control device that can control even when a systematic error has occurred. An update amount calculation processing circuit manipulates a control angle in accordance with an update amount in order to control steering torque, which is obtained by subjecting the magnitude of steering torque to a decrease correction by a threshold, to target torque through feedback control. The control angle is used to convert a current command value to a value in a fixed coordinate system or the like. The update amount is subjected to a guarding process in accordance with the steering torque by a torque-based guarding processing circuit, and determined as a final update amount for the control angle. The torque-based guarding processing circuit performs the guarding process on the update amount such that the update amount is in an allowable range that matches the steering torque.

Steering control device

A steering control apparatus is provided which suppresses possible vibration of a steering system resulting from differential steering processing when a steering angle or a steered angle has a large value. A differential steering processing circuit calculates a differential steering correction amount based on a difference value of a target steering angle, and increases or reduces the target steering angle using the calculated amount to obtain a target steered angle. A limiting reaction force setting processing circuit increases a limiting reaction force when a maximum value of the target steering angle and the target steered angle is equal to or larger than a common threshold. When the maximum value approaches the common threshold, an angle-sensitive gain setting processing circuit reduces an angle-sensitive gain so as to correct and reduce the differential steering correction amount.

Provided is a steering control device that more appropriately performs a limiting function for a controlled variable having an abnormal value even if a plurality of kinds of state quantities that are used for steering control include a state quantity that does not meet a required level of reliability. The range of variation in first assist controlled variable calculated by using steering torque, a steering torque differential value, and a steering velocity, namely state quantities for which the required level of reliability is ensured, is limited by final limiting values calculated based on first to third limit maps. The range of variation in compensation amount calculated by using a steering angle, namely a state quantity for which the required level of reliability is not ensured, is limited by predetermined upper and lower limits. A variation in compensation amount per unit time is limited by a predetermined variation limiting value.

An update amount calculation processing circuit manipulates a control angle based on an update amount in order to perform feedback-control for causing a steering torque to be adjusted to a target torque. In this case, the update amount calculation processing circuit executes a guard process on the update amount with reference to an estimated amount of change that is a speed equivalent value based on estimation by an induced voltage observer. However, when a command current set by a command current setting processing circuit is zero, the update amount calculation processing circuit determines the estimated amount of change subjected to the guard process to be the update amount. When the command current is zero and the update amount is fixed to a guard value, an electric path between the synchronous motor and a battery is blocked.

A steering control apparatus includes a steering angle feedback processing unit and an operation signal generation processing unit that operate a reaction force actuator to adjust a steering angle to a target steering angle that is a target value for the steering angle based on feedback control, an ideal-axial-force calculation unit that calculates an ideal axial force, a road-surface-axial-force calculation unit that calculates a road surface axial force, an axial-force allocation calculation unit that calculates a base reaction force in which the ideal axial force and the road surface axial force are allocated in a predetermined ratio, and a target steering angle calculation processing unit that sets a target steering angle based on the base reaction force. The steering angle feedback processing unit feeds back the target steering angle in which road surface information is incorporated through the road surface axial force, so that the steering angle is controlled.

Restriction values (upper limit and lower limit) for an assist control amount are set individually for each of state amounts including steering torque &#x3c4; used to compute the assist control amount. A value obtained by summing such restriction values is set as a final restriction value for the assist control amount. Even though the assist control amount with an abnormal value is computed, the assist control amount is restricted to an appropriate value by the final restriction value. In addition, a transition is made from a primary assist control amount which is restricted to a secondary assist control amount computed separately from the primary assist control amount at the timing when a certain time elapses since the assist control amount is restricted. As the steering torque &#x3c4; is increased, the speed of transition from the primary assist control amount to the secondary assist control amount is increased.

Growing community of inventors

Tajimi, Japan

Hidenori Itamoto