Tilt Angle Sensor Picture Book 8_Vehicles and Ships

G. Vehicles and ships

The inclination sensor is installed on the vehicle and ship to monitor the tilt attitude angle and acceleration while driving. When the vehicle or ship body exceeds 35°, there is a risk of rollover, so the inclination angle cannot exceed 35°. When the vehicle hull angle is greater than 15°, an alarm signal is required. If necessary, corresponding protective measures should be taken or the motor of the hull should be forcibly stopped to ensure the safe navigation of the vehicle and ship.

Case 1: Inclination sensor vehicle body auxiliary leveling device

1. Overall project requirements

a) Convert the inclination angles of the car body platform in two directions measured by the inclination sensor into the vertical adjustment amounts of the four support points, and output them on the display interface to provide the operator with the basis for adjustment.

b) Detect the level condition of the car body platform and give an alarm reminder when it is out of tolerance.

2. Mathematical calculation model deduction:

a) Determination of standard horizontal plane

Take any standard horizontal section M of the vehicle body, and simplify the four adjustment supports of the vehicle body into the four endpoints A, B, C, and D of two perpendicular intersecting line segments located in the horizontal plane M. The intersection point is the center point of the horizontal plane. O, as shown in Figure 1:

Figure 1 Schematic diagram of the standard horizontal plane of the car body

a) Establishment of calculation model

Under normal circumstances, the initial state of the horizontal plane of the vehicle body is generally in an inclined state. Any tilted plane can be realized by rotating a horizontal plane in two steps: when a plane is tilted, its tilted state can be decomposed into two perpendicular intersecting straight line segments in the plane, each tilting the same or The states formed at different angles, as shown in Figure 1, when the plane M is tilted, can be decomposed into the first step: rotate the plane by an angle α with CD as the rotation axis, the second step: then rotate the plane with CD as the rotation axis. AB rotates the axis of rotation through an angle β. In other words, any tilted plane can be returned to a horizontal state by rotating the plane by an angle -α with CD as the rotation axis, and then rotating the plane by an angle -β with AB as the rotation axis. α and β here are the inclination angles of the plane along the AB axis and CD axis, which can be measured by a high-precision dual-axis horizontal sensor system in this project. From this, through a series of mathematical calculations, the values of the respective heights Ha, Hb, Hc, and Hd required for the tilted plane M to return to the horizontal state can be obtained by adjusting the four pivot points A, B, C, and D. The process is as follows:

First, further transform and set the above process. When rotating, translate the rotation axis to the two straight lines passing through point A and point C of plane M, and determine the direction of rotation as point B downward and point D downward. When When the rotation angle is not large (no more than 10o in this project), the second rotation is considered to be the initial state where the plane is still horizontal. During the first rotation, the descending heights of the four points A, B, C, and D are respectively Ha1, Hb1, Hc1, and Hd1. The descending heights of the four points A, B, C, and D during the second rotation are respectively Ha2, Hb2, Hc2, Hd2, and finally the total heights dropped by the four points A, B, C, and D are Ha, Hb, Hc, and Hd respectively.

In the first step, as shown in Figure 2, the calculation plane takes the side line where CD moves parallel to point A as the rotation axis. When rotated clockwise by an angle α, point B rotates to the position of point B1. At this time, the height of fulcrum A remains unchanged ( That is, Ha1 is 0), the height of point B drops to point B1, the drop distance is Hb1, and points C and D drop by Hc1 and Hd1.

Figure 2 Schematic diagram of the first rotation calculation

In the second step, as shown in Figure 3, the calculation plane uses the side line where AB moves parallel to point C as the rotation axis. When point D rotates downward by an angle β, point D rotates to the position of point D2. At this time, the height of fulcrum C is not Change, the height of point D decreases by Hd2, point A decreases by Ha2, and point B decreases by Hb2.

Figure 3 Schematic diagram of the second rotation calculation

Through the above analysis and calculation, a solution can be drawn: In this project, when the horizontal plane of the car body is in an inclined state, the lengths connecting the four adjustment supports A and B, C and D are known, and the horizontal lengths along the AB and CD directions are known. The inclination angles α and β can be measured by the inclination angle sensor, and the adjustment amounts Ha, Hb, Hc, and Hd is adjusted so that the vehicle body is adjusted from a tilted state to a horizontal state.

3. Determination of adjustment methods in actual operation

a) In the process of establishing the calculation model, we adopt the method of setting both transformations to rotate clockwise. However, in actual situations, the angle of the two rotations that synthesize the final effect may be clockwise or counterclockwise. This is reflected in the calculation model that the α and β angles may take positive or negative values, which in turn makes The final adjustment values of the four adjustment points are also positive or negative, that is to say, when the operator adjusts the height of the four outriggers, some need to be raised and some need to be lowered.

The initial position of the car body can generally only be adjusted higher but not lowered. This requires appropriate conversion to convert the adjustment values of the four adjustment points. First, determine the adjustment point with the highest relative height and adjust it. The height is not adjusted, which saves the workload and adjustment time of the adjustment personnel; the second is to convert the adjustment amounts of other adjustment points into only adjusting them higher and not lowering them to adapt to the actual terrain conditions of the position operation.

Parameter conversion plan: Sort the four calculated values, take the adjustment point with the minimum value as the highest point, do not adjust, subtract the adjustment value of the minimum point from the adjustment values of the other three points, and set it to these three points The final upward adjustment value is output to the display for operator use.

b) Combined with the specific positive and negative direction settings of the inclination sensor angle and the sensor installation direction, determine the positive and negative relationship between α and β angles in the calculation model.

  The positive and negative relationship between sensor angles corresponding to the above calculation model is as follows:

If the specific sensor direction setting or installation direction does not match the above figure, the positive and negative angles of α and β should be changed accordingly according to the specific conditions.

Case 2: Vehicle wiper angle measuring instrument

1 Function and accuracy requirements:

a) Able to measure the rotation angle of the left and right wiper output shafts (mainly measuring the angle of the wiper output shaft at the wiper starting position and wiper limit position relative to the reset position, as shown in Figure 1), and the rotation plane is tilted to the horizontal plane.

b) The fastest wiper rotation speed is 132 cycles/minute, and the angle display speed must be fast enough to ensure that the minimum and maximum angles of a single cycle can be read, or the minimum and maximum angles within a period of time can be recorded and displayed. All data are displayed on the computer and can be printed.

c) The angle measurement range is 90° (can measure clockwise and counterclockwise), and the measurement accuracy is ±0.1°.

Figure 1 Wiper wiping angle diagram

2. Installation interface:

The installation position of the angle measuring instrument is shown in Figure 2, located at the connection between the wiper arm and the motor output shaft. The screws and washers at the connection are removable for installation of the angle measuring instrument, as shown in Figure 3.

Figure 2 Schematic diagram of the installation position of the angle measuring instrument

Figure 3 Schematic diagram of wiper output shaft and brush arm installation

The G800-A micro series angle sensor integrates MEMS technology, is small in size, and has low power consumption. It adopts magnetoelectric induction technology, uses differential array magnetic sensitive elements, and non-contact angle measurement to measure the rotating shaft. It uses a permanent sensor installed at one end of the rotating shaft to sense The parallel magnetic field strength of the magnetic magnet is processed by the MCU to implement programmable intelligent control of linearity correction, temperature compensation, standardized digital filtering of the output signal, zero point setting, and multiple different slope settings to achieve the absolute angle of the output sensor within the range of 0 to 360°. Location. Accuracy 0.3°, multiple outputs RS232, RS485, RS422, CAN, 0-5V, 0.5-4.5V, 0-10V, 4-20mA, 0-20mA optional.

All products have been calibrated, protected against reverse and pulse spike voltages, and tested for long-term aging stability before leaving the factory. Each process is precise and rigorous, and high-quality bearings are used to ensure reliability under different working conditions and long-term use cycles; it has non-contact point, long life, high resolution, low temperature drift, excellent linearity, precise reset, high frequency response, multiple protections, anti-interference, vibration and impact resistance, suitable for water, oil, gas and other harsh industrial environments, making it a cost-effective angle sensor. It is also an ideal product for the replacement of contact angle sensors (such as conductive plastic potentiometers, encoders, and angular displacement sensors).

Figure 5 Schematic diagram of windshield wiper operation

Case 3: Inclination sensor is used in vehicle-mounted system wireless positioning anti-theft tracking system

The vehicle load wireless positioning and anti-theft tracking system receives vehicle sensor fusion information through the vehicle main controller, obtains GPS satellite positioning information through the GPS module, and then communicates bidirectionally with the user terminal through the public mobile communication module through the public mobile communication base station, and emits local sound. Light alarm, GSM wireless transceiver, realize mobile and instantaneous control, characterized in that the sensor fusion information is extracted from the infrared sensor, vibration sensor, Hall switch element and air pressure sensor triggered by the inclination sensor, microwave Doppler sensor, Obtained after fusion and adjudication, the user terminal issues control instructions to the main controller after passing identity verification, realizing intelligent automatic monitoring with zero false alarms.

The T700-H inclination sensor developed and produced by Maixinminwei can be well used in this control system, the control part and the execution part. The inclination data collection part includes the inclination sensor with its own GPS module and the signal output interface of the inclination sensor. With the analog-to-digital conversion interface of the microcontroller in the control part, the signal end of the ignition lock is connected to the input and output interface of the microcontroller; the microcontroller is connected to the GSM module through the serial port; personal information such as the user's mobile phone number is preset in the microcontroller. The execution part includes a control circuit that controls the relay of the vehicle's main control power supply and is connected to the input and output interface of the single-chip computer, and the vehicle alarm system is connected to the input and output interface of the single-chip computer. The inclination sensor can not only measure the form and attitude of the vehicle body, but also provide the location of the vehicle, provide reliable longitude and latitude for the tracking system, and shorten detection time.

Case 4: Car four-wheel alignment

From the structure of the car, the installation between the steering wheel (front wheel), steering knuckle and front axle of the car has a certain relative position. This installation with a certain relative position is called steering wheel alignment, also called front wheel alignment. . Front wheel alignment includes four contents: kingpin caster (angle), kingpin inclination (angle), front wheel camber (angle) and front wheel toe-in. For the two rear wheels, there is also a relative position installed between the rear axle, which is called rear wheel positioning. Rear wheel alignment includes wheel camber (angle) and rear wheel toe-in one by one. This front wheel alignment and rear wheel alignment are collectively called four-wheel alignment.

When the vehicle leaves the factory, the positioning angle is preset according to the design requirements. These positioning angles are used together to ensure the comfort and safety of vehicle driving. However, after the vehicle is sold and driven for a period of time, these positioning angles may change due to traffic accidents, severe bumps caused by potholes on the road (especially sudden bumps when driving at high speed), wear and tear of chassis parts, and replacement of chassis parts. , tire replacement and other reasons. Once the positioning angle changes due to any reason, uncomfortable symptoms such as abnormal tire wear, vehicle deviation, reduced safety, increased fuel consumption, accelerated wear of parts, heavy steering wheel, and floating vehicle may occur. Some symptoms make driving at high speeds very dangerous.

Four wheel aligner

The purpose of four-wheel alignment repair and maintenance services is to diagnose and treat the above-mentioned causes of vehicle discomfort through alignment angle measurement. Generally, a new car should have a four-wheel alignment after driving for 3 months. After that, every 10,000 kilometers of driving, tires or shock absorbers should be replaced, and a four-wheel alignment should be done promptly after a collision. Correct wheel positioning can ensure flexible steering, comfortable riding, maintain straight driving, extend tire life, and reduce vibrations caused by the road surface.

Most of the instruments currently responsible for wheel alignment testing are "four-wheel aligners." During testing, the four-wheel aligner first measures the current four-wheel alignment parameters of the car, and then the computer automatically compares them with the stored values of the corresponding vehicle model to determine the four-wheel alignment parameters of the car. The deviation value is calculated after positioning, and the maintenance personnel can make corrections according to the prompts of the locator and then restore the original position.

Inclination sensor in wheel aligner

For different four-wheel alignment equipment, the key role is whether the measurement sensor is accurate. Modern cars generally use front and rear independent suspension. The main parameters detected by the four-wheel aligner are wheel camber angle, kingpin caster angle, kingpin inclination angle and toe-in and other parameters. For the measurement of the above inclination angles by the four-wheel alignment measurement system, except for the toe angle, which is generally achieved through a turntable or angle sensor, inclination sensors are generally used for other angles. The inclination sensor is fixed on the mounting base of the four-wheel aligner, and then installed on the wheel of the car through a clamp.

Due to the structure of the car, the inclination angle measurement in the wheel alignment angle of the car is divided into two types: direct measurement and indirect measurement. It can be seen from the definition of wheel inclination that wheel camber can be measured directly using an inclination sensor, but this is not the case for kingpin inclination and caster. Since the kingpin is installed on the inside of the wheel, it generally cannot be measured directly through the inclination sensor. to measure. The wheel inclination angle measurement range should be approximately ± 15°. For models in use today, the adjustment deviation value of the inclination angle is generally about 5'. For example: the Volkswagen PASSAT B5 front wheel camber angle value is -0 ° 35' to ± 0 ° 25', so the measurement resolution of the sensor should be less than or equal to 5 '.

Case 5: Inclination sensor is used to detect the running attitude of ambulances

Ambulances are an indispensable means of transportation in any country. They are also manned vehicles used to rescue patients. Currently, the ambulances carry splints and brackets to fix the patient's broken limbs and prevent the patient's neck and spine from getting aggravated.

In recent years, the application of sensors can be said to be ubiquitous in engineering equipment, transportation and other industries, but the application of inclination sensors in the medical industry is very rare. Currently, inclination sensors are being used on many ambulances. So, what are the specific applications of inclination sensors in ambulances?

Ambulances are an indispensable means of transportation in any country. They are also manned vehicles used to rescue patients. Currently, the ambulances carry splints and brackets to fix the patient's broken limbs and prevent the patient's neck and spine from getting aggravated. The ambulance is also equipped with oxygen, portable ventilators and pacemaker-defibrillators. Most ambulances also have patient monitors that can monitor the patient's pulse and breathing on the way to the emergency room. At the same time, these detection data can be sent to the hospital via radio, allowing the hospital to monitor the ambulance in real time.

An ambulance driver can drive quickly without tilting the body around corners or bumping on uneven roads, which requires excellent driving skills and high concentration. It can be said that this is not just the driver's skill. How can the driver know whether and how much the ambulance is tilting while driving and turning? This is the function of the inclination sensor on the ambulance. The dual-axis inclination sensor measures the inclination angle of the ambulance. Not only that, the use of the inclination sensor provides a reliable basis for the selection of ambulance drivers. It can not only measure the inclination angle of the ambulance but also measure the inclination angle of the ambulance. The current tilt angle of the sensor is measured, and the data can be displayed in real time through LED/LCD. The relevant data can also be recorded through integrated software to facilitate viewing of historical data. In this way, the role of the tilt sensor cannot be eliminated. . The inclination sensor has become mature as a means of detecting the running attitude of ambulances. In the future, these data will be detected in real time in hospitals.

Case 6: Ship inclination monitoring system solution

 The "Ship Inclination Monitoring System" replaces the currently temporarily adopted horizontal instrument observation method. The specific implementation plan is as follows.

1. System Features

The "ship inclination monitoring system" and the original "six-point draft monitoring system" do not interfere with each other, but can complement each other. The "ship inclination monitoring system" can realize the functions of real-time display of inclination angle, over-limit alarm reminder, data storage and on-demand customization, making up for the shortcomings of the "six-point draft monitoring system" which only displays the ship's draft.

2. Implementation ideas

a) One dual-axis inclination sensor is arranged at the bow of the ship and is connected to the terminal display arranged on the load-adjusting console via wires to facilitate observation by the load-adjusting personnel. Compare with the reference of the LED inclination display in the ship to achieve dual-machine redundancy and avoid the failure of a single sensor to monitor the ship's inclination and affect the construction.

b) A dual-axis inclination sensor is arranged in the ship and connected to the LED large-screen display in the ship through a wired method. It is conspicuous and easy to read, which facilitates on-site command to flexibly command according to the ship's status. It can also be used for daily real-time monitoring of the ship's floating status, and with It has an over-limit alarm reminder function. When there is no need for load adjustment during small swing hoisting, the load adjustment console does not require dedicated personnel to be on duty.

c) Arrange a wireless dual-axis inclination sensor at the stern and connect it wirelessly to the terminal display arranged in the crane cab (wireless transmission needs to be determined after on-site test signal stability).

The system diagram is as follows:

3. Equipment selection

a) Sensor

b) display terminal

c) LED display screen: This display screen needs to be customized, and the display effect is as shown in the figure below:

Case 7: Application of inclination sensor to monitor ship navigation attitude

The inclination sensor is generally installed on the horizontal platform of the ship deck and is used to measure the inclination angle of the ship itself when the ship is traveling or docking. When the ship body exceeds 35°, there is a risk of capsizing, so the inclination angle cannot exceed 35°. When the angle of the hull is greater than 15°, an alarm signal is required. If necessary, corresponding protective measures should be taken or the motor of the hull should be forcibly stopped to ensure the safe navigation of the ship, especially in the case of wind and waves, so the inclination sensor is also required. It has become an indispensable measurement tool for the safe operation of ships.

Case 8: Monitoring application of inclination sensor in sand mining ship

Sand mining ship, fishing boat is a fishing vessel, a collective name for ships that can catch, process, and transport fish. Fishing vessels are vessels that capture and harvest aquatic animals and plants, and also include some auxiliary vessels for modern fishing production, such as vessels for aquatic product processing, transportation, breeding, resource surveys, fishery guidance and training, and fishery administration tasks.    

Most fishing vessels are small. However, in order to adapt to continuous navigation and operation in wind and waves, they are required to have good stability, seakeeping and seaworthiness, and the structure needs to be particularly strong. The load capacity of fishing boats changes greatly during operation, ranging from tens to hundreds of tons for small and medium-sized fishing boats, to thousands of tons for large fishing boats, or even more than 40,000 gross tons.

In addition to the general marine equipment, fishing boats also need to be equipped with fishing aids and navigation and communication instruments such as winches, inclinometers and navigators. In particular, the inclinometer plays a very important role for the driver. The inclinometer, also called an inclination sensor, is an instrument that measures the inclination angle of an object in real time. The inclinometer can measure the real-time pitch angle and roll angle of a fishing vessel in real time. comes out and can be displayed through corresponding display instruments, so that the driver can control the current operating status of the ship in real time and adjust the operating direction in time, making it easier to maintain the stable operation of the ship. At the same time, it has gradually become the most commonly used and indispensable tool for drivers. one of the instruments.