JPH01174970A - Rudder steering angular speed detector - Google Patents

Abstract

PURPOSE:To enable continuous reading of an angular speed signal corresponding to angle of rotation, by using two single-rotation potentiometers to read out any of first and second rudder steering angular speed signals according to the size of first and second steering angle signals. CONSTITUTION:Single-rotation potentiometers 1, 2 output steering angle signals theta1 and theta2 with the phase differing by 180 deg. from each other with respect to a certain angle, namely, an angle of rotation. Then, first and second angular speed detection circuits 3 and 4 input the signals theta1 and theta2 to output steering angular speed signals theta'1 and theta'2. Then, the signals theta'1 and theta'2 and steering torque signal T are inputted into an A/D converter 5 to be converted into digital signals and inputted into a microprocessor unit MPU 7. The signals theta1 and theta2 and a motor current signal I are inputted into an A/D converter 6 to be converted into digital signals and inputted into the MPU 7. Moreover, a vehicle speed V is inputted thereinto 7. Then, the MPU 7 reads out any of first and second steering angular speed signals according to the size of the first and second steering angle signals to be outputted to a motor driving circuit through a PWM output section 8.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a steering angular velocity detection device using two one-rotation potentiometers, and particularly relates to a steering angle detection device suitable for use in an electric steering booster. It is something.

[Conventional technology]

Conventional steering angular velocity detection devices include devices that use a single-rotation potentiometer for multiple rotations, devices that use a multi-rotation potentiometer, and the like.

[Problem that the invention seeks to solve]

An electric steering booster that calculates a basic instruction value for the motor based on the steering torque applied to the steering wheel, corrects the calculation result based on the steering angular velocity of the steering wheel, and rotates the motor to perform auxiliary steering. In the device, it is necessary to detect the steering angular velocity over the entire lock-to-lock range, but when a single-turn potentiometer is used for multiple turns, there is a dead zone and there are parts that cannot be used for control. Additionally, multi-rotation potentiometers have accuracy problems due to the backlash of the built-in reduction gear, and when converting the entire steering range from A/D to A/D, a more accurate and expensive A/D converter is required compared to a single-rotation potentiometer. I need.

The present invention has been made in view of these points, and its purpose is to provide a steering angular velocity detection device that does not produce a dead zone, is highly accurate, and does not require an expensive A/D converter. It is in.

[Means for solving problems]

In order to achieve such an object, a steering angular velocity detection device according to the present invention includes first and second one-turn potentiometers that detect a steering angle and output first and second steering angle signals; an angular velocity detection circuit that differentiates a second steering angle signal and outputs first and second steering angular velocity signals; A reading means for reading any of the steering angular velocity signals is provided.

[Effect]

The steering angular velocity detecting device according to the present invention does not produce an unsteady zone,
It is highly accurate and does not require an expensive A/D converter.

〔Example〕

The present invention provides two economical one-turn potentiometers, one
They are connected in tandem with a phase shift of 80 degrees, and the output voltage of one potentiometer is detected, and when that voltage approaches the fuwa zone, control is performed using the output voltage of the other potentiometer.

FIG. 1 is a system diagram showing an embodiment of a steering angular velocity detection device according to the present invention. In FIG. 1, 1 is a first one-turn potentiometer that detects a steering angle and outputs a first steering angle signal θ, and 2 is a second potentiometer that detects a steering angle and outputs a second steering angle signal θ2. 3 is a first angular velocity detection circuit that inputs a steering angle signal θ1 and outputs a steering angular velocity signal θ1; 4 is a second angular velocity that inputs a steering angle signal θ2 and outputs a steering angular velocity signal θ2. a detection circuit; 5 is a first A/D converter into which steering angular velocity signals θ, θ2 and steering torque signal T are input; 6 is a first A/D converter that receives steering angle signals θ1, . θ2
and a second A/D converter that manually inputs the motor current signal 7
is a microprocessor unit (hereinafter abbreviated as rMPUJ) that performs overall control and inputs the vehicle speed signal V.
, 8 is a PWM output section that outputs a PWM signal, 9 is a ROM
, 10 is a RAM. Further, 31 and 32 are a buffer circuit and a differential circuit that constitute the angular velocity detection circuit 3;
Reference numerals 1 and 42 are a buffer circuit and a differentiating circuit that constitute the angular velocity detection circuit 4. The above A/D converter 5.6 and M
PU7 constitutes a reading means.

Next, the operation will be explained using FIG. 2. Potentiometers 1 and 2 are connected in tandem with a 180 degree phase shift. Since the output voltage of the potentiometer 1.2 is as shown in FIGS. 2(a) and 2(b), the differential values of the differentiating circuits 32, 42 also lose continuity at discontinuous points. Therefore, in this device, the actual output voltage of the potentiometer is detected, and based on that value, a more suitable one is selected from the differential values of the two potentiometers, and is used as the steering angular velocity.

To explain in more detail, the potentiometers 1 and 2 output steering angle signals θ1 and θ2 having phases different from each other by 180 degrees with respect to the steering angle, that is, the rotation angle. For example, in FIG. 2 (al), point P1 is at a position of about 270 degrees, and the steering angle signal θ is at this position.

outputs a signal with voltage θ□8, and steering angle signal θ2 outputs a signal with voltage θ
Outputs the MIN signal. However, about 9 degrees shifted by 180 degrees
At point P2, which is the 0 degree position, the steering angle signal θ1 outputs a signal of voltage θ□9, and the steering angle signal θ2 outputs a signal of voltage θMA
Outputs the X signal. Therefore, when the voltage Vθ of one potentiometer is within the range of θ□8≦■θ≦θMAX, the steering angular speed of this potentiometer is selected, and when it is outside the above range, the voltage of the other potentiometer is within the above range. Therefore, by using the steering angular velocity of this potentiometer, it is possible to continuously capture the steering angular velocity signal corresponding to the rotation angle without any dead zone. In this case, the voltage θWAX becomes the maximum detected voltage, and the voltage θHIM becomes the minimum detected voltage.

FIG. 3 is a circuit diagram showing the angular velocity detection circuits 3 and 4 of FIG. 1 in detail.

FIG. 4 is a flowchart for explaining the operation of the apparatus shown in FIG. 1, and shows a routine for reading angular velocity. Next, the operation of the apparatus shown in FIG. 1 will be explained using this flowchart. First, it is determined whether the potentiometer selection flag is off or not (step 11). If it is off, the process proceeds to step 12, where it is determined whether the steering angle signal θ1 is smaller than the maximum detection voltage θMAX. Proceeding to step 13, it is determined whether the steering angle signal θ1 is greater than the minimum detection voltage θ, 41N. If it is larger, the angular velocity b1 is read in step 14. In other words, the steering angle signal θ1 is the maximum detected voltage θﾆX and the minimum detected voltage θ40
, the signal j1 is read as an angular velocity signal. If not, the process proceeds to step 15, where the selection flag is turned on, and in step 16, the signal δ2 is read as an angular velocity signal.

If the selection flag is not off in step 11, the process moves to step 17, and this time it is determined which angular velocity signal to read based on the steering angle signal θ2 (steps 17 to 19).
). The operation is the same as that for the steering angle signal θ1, so a description thereof will be omitted.

In this embodiment, θ3. Although the usable range of θ2 is each 180 degrees, it is not limited to 180 degrees, and it is possible by complementary sharing the range of one rotation.

In this way, by selecting and reading the appropriate one of the signals θ and 02 of the potentiometers 1 and 2, the angular velocity signal corresponding to the rotation angle can be read continuously without any dead zone.

Furthermore, the potentiometer 1.2 is a single-turn potentiometer with high precision, and does not require a high-precision A/D converter for the angular velocity signal as in the case of a multi-turn potentiometer.

〔Effect of the invention〕

As explained above, the present invention differentiates the first and second steering angle signals output from the one-turn potentiometer to output the first and second steering angular velocity signals, and outputs the first and second steering angular velocity signals. By reading either the first steering angular velocity signal or the second steering angular velocity signal depending on the magnitude of the steering angle signal, the effect is that the angular velocity signal corresponding to the steering angle can be read continuously with high accuracy without a dead zone. be. Furthermore, since a one-turn potentiometer is used, there is an advantage that a highly accurate and expensive A/D converter is not required.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an embodiment of the steering angular velocity detection device according to the present invention, Fig. 2 is a graph for explaining the operation of the device shown in Fig. 1, and Fig. 3 is a configuration of the device shown in Fig. 1. FIG. 4 is a circuit diagram showing the angular velocity detection circuit in detail, and FIG. 4 is a flowchart for explaining the operation of the device shown in FIG. 1.2... Potentiometer, 3.4... Angular velocity detection circuit, 5.6... A/D converter, 7... MPU,
8...PWM output section, 9...ROM, 10...R
AM, 31.41...Buffer circuit, 32.42...
・Differential circuit. Patent applicant: Automotive Equipment Co., Ltd. Fujitsu Limited

Claims (1)

[Claims] first and second one-turn potentiometers that detect a steering angle and output first and second steering angle signals; and first and second steering angular velocities that differentiate the first and second steering angle signals. an angular velocity detection circuit that outputs a signal;
A steering angular velocity detection device comprising: reading means for reading either the first steering angular velocity signal or the second steering angular velocity signal depending on the magnitude of the steering angular velocity signal.