JPH04176786A - Electronic control system for stair climbing vehicle - Google Patents

Abstract

PURPOSE: To provide an electronic control device for a stair climbing vehicle such as a wheelchair by determining an inclination of stairs in response to a front and a back ranging sensors, and prohibiting motion on the stairs beyond specified geometric characteristics. CONSTITUTION: In normal conditions, a wheelchair moves along the horizontal ground, constantly checks a sonar (ultrasonic transducer) to dropping in a vertical direction, and checks an inclination gauge 274A. Inclination of a seat part is adjusted by reading the number in the inclination gauge 274A, and holding a user in the vertical direction. As an upward vertical direction inclination of stairs as a sufficient inclination is detected, the wheelchair is transferred to a stair mode, and inclination of stairs, that is of a ramp, is computed based on a traveling distance by encoders 70, 72 and a height of the stair by an ultrasonic sensor 76. When the ramp, or the stair is excessively sharp, further advance is prohibited, and when the ramp or stair is not excessively sharp, the seat part of the wheelchair is adjusted to the lowest stable angle at a top part of the ramp or stair.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for controlling the operation of a human transport vehicle, such as a wheelchair, during ascending and descending stairs.

(Prior Art and Problems to be Solved by the Invention) A major challenge for wheelchair designers has been to design a wheelchair that can move up and down stairs safely and effectively, without being too troublesome, cumbersome, or expensive. . One such design is shown in US Pat. No. 4,674,584. The wheelchair runs on conventional wheels during horizontal operation and has ultrasonic sensors to detect the presence of stairs or other inclines. The sensor signals are used to raise and lower a pair of endless tread loops.

Besides lowering the track, the signals from the ultrasonic sensor are also used to detect if the slope is too steep for the wheelchair to handle. In such cases, the wheelchair cannot move forward and up and down the stairs.

One problem with stairwelling is that as the wheelchair descends the stairs, it can tilt suddenly and hit the stairs, potentially shaking or injuring the user.

A solution to this problem is found in U.S. Patent No. 4,671,369.
listed in the number. The front and rear arms are positioned under the wheelchair and extend downwardly over the stairs as the wheelchair approaches the stairs. As the body of the wheelchair begins to tilt down the stairs, the arms are already resting across the steps of the stairs.

A damping fluid-filled cylinder between the extended arm and the wheelchair body ensures that the wheelchair body slowly transitions to a downwardly facing position on the stairs. The damping means is simply a fluid that slowly moves the piston through a tube and cylinder through which the piston extends. Said Patent No. 4,671,369
No. indicates a mechanical linkage for locating the shock absorbing arm.

In order to give the user maximum comfort while ascending the stairs, the seat is tilted so that the user remains parallel while the body of the wheelchair is tilted.

This tilting motion is also necessary to shift the center of gravity of the wheelchair and user to the appropriate position for safe ascending the stairs. If the center of gravity moves too far forward and away from the stairs, the wheelchair may tip over. Thus, if this tilting mechanism is not provided and the center of gravity is not controlled accordingly, there is a risk that the wheelchair will tip over.

Power-driven wheelchairs come in a variety of types depending on the abilities of the person using the wheelchair. Certain wheelchairs have stair climbing and other capabilities.

A control stick is used as a typical input mechanism to control both the speed and direction of the wheelchair. However, since wheelchair users are often unable to operate the control stick due to discomfort, other input mechanisms include voice-controlled hand gear that responds to head movements, and blowing through a straw. and includes an air pressure sensor that responds to suction. Depending on the type of input means used, the input circuitry may need to be modified to process the input signals and responsively provide appropriate drive signals to the wheelchair motors.

Further, there are variations depending on the user for a particular type of input, such as a control stick.

For example, some users cannot easily operate the control stick because they are constantly shaking their head. Thus, special filter circuits can be included to eliminate such extortion effects. Furthermore, the user can only make jerky movements, which can cause them to accelerate or decelerate very quickly without correction. Such modifications can be implemented using separate circuitry or by providing a switch as an input to the processing unit on the back of the wheelchair, which can be configured according to the requirements of a particular user. . The use of such a switch complicates the circuitry and is additionally costly since it requires a technician to configure the wheelchair for a particular user. For example, US Pat. No. 4,634,941 discloses in column 8 the use of variable resistors to control acceleration and deceleration.

Some wheelchairs are used in environments with a large number of users, such as, for example, sanatoriums, where it is necessary to reconfigure the wheelchair each time it is provided to a new user. Furthermore, access to the wheelchair must also be controlled if the wheelchair is not tailored to the user's particular discomfort and could potentially cause injury to the particular user.

(Means and effects for solving the invention) The present invention provides an electronic control device for a stair-climbing vehicle such as a wheelchair.
Front and rear sensors are provided to detect stairs or slopes. The child controller determines from the sensor data whether the slope is an acceptable slope for driving. If not allowed, the vehicle will be prevented from entering the staircase or slope.

The seat for the user is tilted by electronic control to keep the user generally perpendicular to gravity as the vehicle travels down the stairs. Permissible operation of the vehicle is controlled through parameters that can be changed by removable memory to configure the vehicle for a particular user or group of users.

In certain embodiments, the vehicle descends the slope in a forward direction, and the slope is lowered before the wheelchair reaches the slope, such as the 0 steps, where the ascent of the slope is directed backwards. A sensor is provided to detect the angle. A seat tilt control signal is provided to the motor to tilt the seat to a predetermined minimum safe angle before the wheelchair reaches the stairs. The minimum safe angle is the tilting angle at which, even if the tilting mechanism were to fail, the wheelchair would tip over and the seat would not fully pivot to the vertical position when traveling up stairs. The minimum safe angle depends on the location of the wheelchair's center of gravity as affected by the user's weight. If the seat does not achieve this minimum tilt, the wheelchair will be prevented from climbing the stairs.

Contains a key code that allows only authorized users or groups of users to operate the vehicle, and constants used in algorithms to operate the vehicle according to specifications for the needs of that particular user or group of users. A removable programmable memory is provided.

Control signals from an input means, such as a control stick, are modified by an algorithm according to specifications for a particular user or group of users to control responsiveness, acceleration rate, maximum speed, etc. This specification is stored in programmable memory and loaded into the computer when the memory is inserted. Key codes in memory allow various levels of access, such as access to specific users, specific groups of users, access to doctors, and access to technicians.

A pair of inclinometers is provided. The first inclinometer detects fluctuations from the Y axis from the front to the rear of the vehicle, ie, fluctuations from the horizontal position by tilting back and forth. The second inclinometer detects deviations from a Y-axis extending from one side of the vehicle to the other, or in other words, tilting from one side to the other. As the vehicle moves up and down the stairs, the angle of the stairs is first calculated to determine the default Y-axis variation.

The various variations from the Y axis in combination with the variations from the Y axis are used to calculate the angular displacement between the Y axis of the vehicle and the longitudinal axis of the stairs, i.e. the rotational skew while going up and down the stairs. To detect. Rotational skew beyond a safe amount is then prevented. Therefore, rotational skew that could make the vehicle unstable is automatically prohibited.

The vehicle is provided with front and rear shock absorbing arms to dampen the movement of the vehicle when descending onto the stairs and the movement when landing from the stairs when climbing. During descent, an electronic control unit with sensors determines whether the slope is acceptable for the vehicle and always deploys the damping arm. When climbing,
The buffer arm is used only after the vehicle has moved to the last step and not when it is on the first or intermediate step of the stairs.0 Detection of the inclination of the stairs as well as detection of the presence of the second step is 2 This is accomplished by two rear sensors and a Y-axis tilt needle. The first sensor is oriented at a slight downward angle and the second sensor is oriented at a greater downward angle. This provides two different perspectives for detecting the connection between the "nose" or rise of the rung and the tread (the flat part of the rung on which the legs rest). The first sensor is capable of detecting the stair nose at a greater distance, while the second sensor is capable of accurately detecting the exact location of said nose. For an understanding, reference should be made to the following detailed description in conjunction with the accompanying drawings.

EXAMPLE FIG. 1A shows a wheelchair 210 according to the present invention. For example, the vehicle can be lifted up and down while going up and down slopes such as stairs,
The wheelchair can therefore be operated in normal mode using its wheels. A seat 214 is supported by a column 216. Post 216 may pivot about pivot point 218 by arm 220. Arm 220 is coupled to a motor actuator 222 that moves arm 220 back and forth to tilt seat 214.

A rotational resistance sensor 224 coupled to the bottom of the post 216 is used to detect the actual tilt of the seat.

A pair of forward ultrasonic sensors 226 detect the inclination angle of the surface on which the vehicle approaches. rear ultrasonic detector 228A,
228B is used when the wheelchair is climbing stairs, which is done in the opposite direction.

FIG. 1A also shows inclinometers 274A, 274B that detect the angle of inclination of the wheelchair frame. Inclinometer 274
The signal from A is used to control motor actuator 222 to maintain the seat of spacer 214 in a horizontal orientation (with respect to gravity) during normal operation.

The front and rear shock absorbing arms 230 and 232 are provided to dampen the movement of the wheels of the wheelchair, while the arms 230 and 232 are designed to help the wheelchair slowly transition to the stairs (arm 230) or to climb up from the stairs to the landing point (arm 230). 232).

When the wheelchair is in position to descend the stairs, the solenoid retracts the latch that holds the buffer arm 230 in the up position. Zero gravity causes the buffer arm 230 to descend so that it extends over and contacts the stair steps. . A similar solenoid and latch is used for the rear shock arm 232. The solenoid detects when arm 232 is in the upper position.

An optional sensor detects when the arm is in the down position. Piston and cylinder assemblies 238, 240 couple shock arms 230, 232, respectively, to the wheelchair frame. The upper end of the cylinder 238, 240 is connected to the hose 248
and 250 to a fluid reservoir 254 . This arrangement is shown in Figure 1B.

FIG. 1B is a diagram of the forward cylinder assembly coupled to the forward shock arm 230. The piston 251 is connected to the upper portion 2
55 and a bottom portion 256 to a shaft 253 extending from a hollow cylinder 252 containing fluid. There is a unidirectional fixed orifice 260 inside the piston that restricts only one side. Hose 24B is the upper part 2
55 is coupled to reservoir 254.

Orifice 260 extends from top portion 255 to bottom portion 256;
Or regulate the opposite flow. As the wheelchair frame 264, which is thus coupled to the upper end of the cylinder 252, tilts downwardly on the stairs, the regulated flow of the valve 260 cushions the tilting by slowing the compression by the piston 252. The arm 230 is a motor (
(not shown). When arm 230 is fully raised, sensor 270 (see FIG. 1A) detects that the arm is in the upper position and latched via latch 234.

The preferred fluid for use in cylinder 252 is a silicone-based lubricant. It was chosen because it is a relatively clean fluid, provides the necessary incompressibility, is inexpensive, and
This is because it can be used immediately.

FIG. 1A shows a control frame 16 attached to one arm of the chair along with a control panel 18 having a display and push buttons. The control frame and control panel may be provided on separate arms.

Referring to FIG. 2, control signals from control frame 16 and control panel 18 are provided to command module 20. Referring to FIG. Signals from control panel 18 are provided on address and data bus 22. The signal generated by the variable reluctance sensor from the control frame 16 is an analog signal provided on wiring 24 by an analog-to-digital converter 26 in the command module 20 . A/D
A transducer 26 is coupled to the lotus 22.

The control panel 18 has a display 2 and a push button 30.
and has. The push button is preferably large and easily depressed, and the display 28 uses large font for easy viewing by the user.

The tw order module operates using random access memory (R
AM) 34 and programmable read-only memory (
FROM) 36 and (EEFROM) 37 are used. Key FROM 38 is coupled to bus 22, although it may be coupled directly to microprocessor 32. key F
ROM 38 provides the code that enables the motorized wheelchair to operate and provides algorithmic constants for processing input data and configuring the wheelchair according to specifications for a particular user or group of users. .

Control frame 16 may be replaced with other input devices, such as a straw that uses suction and blow actuation to generate changes in air pressure to an air pressure sensor. These inputs are similarly processed via A/D converter 26.

Key F ROM38 indicates the type of manual power used,
Provides the data required by the micropro sensor 32,
Modify the input data as appropriate for the type of input.

The key PROM contains a key password that is loaded into the EEFROM 37 upon startup of the wheelchair. This password is then stored in the EEFROM 37 and the wheelchair can be activated by means of a specific key PROM 38 with that password. When the key PROM is inserted, microprocessor 32 compares the password to the password stored in EEFROM 37. Alternatively, the user must manually enter the password. Several different levels of key codes can be used, such as, for example, mask (treatment professional and/or field service), group (clinical setting), and individual.

The key FROM is preferably electrically programmable (EEFROM) for easy modification.

The doctor calls the manufacturer with the new specifications and issues a new key PR.
OM can be programmed and sent.

The new key PROM has a code indicating that it has not yet been used. Once the contents of the new key PRON are loaded into EEFROM37, the key FROM38
The code is changed to indicate that it is the key FROM that was used. Thereafter, that key PROM 38 can only be used to activate the particular wheelchair that has the same key stored in its EEFROM 37. moreover,
All of the constants from key PROM 38 are loaded into EEFROM 37 in the command module and key PROM 3
8 provides redundant backup.

The key PROM 38 also contains the constants necessary to modify the wheelchair control algorithms for acceleration, deceleration, jerk rejection, maximum speed (both translation and rotation), and general modes of operation of the wheelchair.

The command module 20 provides two series lines to the control module 44, including a duplex RS 422 interface 40 coupled to a pair of series links 42 to provide asynchronous nature for full duplex communication. 0 communications are received by the RS 422 interface 46 of the control module 44 and provided on the address and data bus 48. Microprocessor50. RAM52 and ROM
54 is coupled to bus 48. control module 44
is a pulse width modulated (PW) coupled to drive device 62.64.
M) providing controlled power to each motor via generator 56; Power supply 58 provides power from a series of batteries 60 and controls the charging of these batteries. PWM generator 56 is PTV wheel motor drive device 6
2. It is connected to another drive device 64 for other motors or a solenoid that controls the position of the seat, the inclination of the backrest, the vertical position of the stair-climbing track, etc.

The motor drive device 62 is connected to left and right wheel motors 66 and 68. Encoders 70.72 are connected to motors 66.
68 is provided to microprocessor 50 via an interface (see FIG. 4).

A number of transducers 74 and ultrasound transducers 76 are coupled via an analog-to-digital converter 78 in control module 44 . Alternatively, a specialized sonar interface 112 can be used as shown in FIG.

Additionally, sensors that provide digital outputs that can bypass A/D converter 78 may be used. These inputs may be multiplexed through a single A/D converter as detailed in FIG.

FIG. 3 shows the command module 20 shown in 2I21 in detail. In addition to the elements shown in FIG. 2, a push button 30 is coupled to the microprocessor bus 22 via a key interface 102 and a second interface 104. The liquid crystal display (LCD) 28 is an LCD driver 106
controlled by Driver 106 is driven by microprocessor 32 by signals on bus 22.

Additionally, a backlight control circuit 108 detects ambient light conditions via a photodiode 110 to control the backlight of the LCD display 28 .

Figure 4 shows the mm module in detail, the ultrasonic transducer 7
6 is coupled to microprocessor bus 48 via sonar interface 112.

Microprocessor 50 sends signals through interface 112 to drive transducer 76 and then monitors the echo signal.

In addition to ultrasound transducers, both digital sensors 114 and analog sensors 116 are provided. Digital sensor signals are provided via digital interface 118 to microprocessor bus 48. Analog sensor signals are provided to microprocessor bus 48 via analog-to-digital converter 120. Furthermore, the monitor signal from the power supply I22 in the power module 58 is
"' is provided via the D converter 120.

The power module 58 includes a power supply 122 and a power control circuit 12
4. Circuit 126 and miscellaneous driver 128 for battery charging 1
This driver 128 is connected to miscellaneous actuators and solenoids 130. Driver 128 is operated by microprocessor 50 via interface 132.

The motor drive module 134 includes a motor shown in the second section,
Furthermore, the signals from the encoder 70, 72 are connected to the encoder interface 1, including drive and encoder elements.
36 to a microprocessor bus 48.

Appendix I shows one basic example of a dual algorithm for controlling a wheel motor, where XLo is the left motor power and XRo is the right motor power. These two algorithms are modified proportional, integral, differential (PI) with element calculations and constants shown in Appendix ■.
D) uses an algorithm. These constants are key F
Provided by ROM38. These are Kt, Kr and Ks. Additionally, the key PROM is connected to drive device 64.
Other algorithm constants or other coefficients of the algorithm can be provided to control other aspects of the wheelchair through the . The constants apply to the filtering algorithm for the command module 20, which is detailed in Appendix 2.

Abendick's filtering algorithm is implemented in the command module 20. Essentially, this provides a dead zone near the center of the control stick and along the X and Y axes so that the user can travel in a straight line without having to hold the stick exactly straight, and It can stay in one place even if it moves a little. Furthermore, the algorithm is more responsive at lower speeds and less sensitive at higher speeds, giving the user more maneuverability at low speeds and preventing sharp turns at higher speeds.

Furthermore, convulsive movements are filtered out.

Key FROM 38 provides various constants and other inputs for the filtering algorithm in command module 20 and the control algorithm in control module 44 to enable certain functions or set certain limits.

Examples of these inputs are:

1. The maximum angle that the user can accommodate (9-36 degrees) 2. The maximum speed that the user is allowed to handle 3. The date of the user's next appointment with the treating professional to be displayed on the display 28. 4. Possibility of entering the trajectory mode that activates the treads of the wheelchair 5. Possibility of entering the 11-step climbing mode 6. Possibility of turning off the voice input mode (for people with severe disabilities 7. Possibility to set the inclination and height of the chair (some users are not allowed to change this).

8. Possibility to switch off the ultrasonic drop-off detector (this is desirable for loading wheelchairs into pans etc.).

9. The range (in miles and/or hours) at which the chair begins to enter the second level of functionality, all of which are programmable as well. This is provided so that the user does not necessarily need the help of a therapist to access more advanced features where certain progress is expected at a given time.

Also shown are a low battery indicator 84, a warning symbol 86, a bell indicator 88, a fuel level indicator 90, and a status indicator 92.

The wheelchair statue 82 is in various shapes Bf! : has several elements that are illuminated to indicate. A basic wheelchair image without any illumination of status indicators is shown in FIG. The various elements shown in FIG. 5 are as follows. First, the high speed mode is indicated by line 94. Operation of the ultrasonic sensor is indicated by an eye and a downwardly directed line 96. The operation of the speech synthesizer is shown by line 98. l1100 indicates that the seat is raised, and line 102 indicates that the backrest is tilted back.

Line 104 indicates that the stair climbing track is in operation. Line 105 indicates that an "easy down" is in place to dampen downward movement on the stairs; such an "easy down" is shown in U.S. Pat. No. 4,671,369. There is.

Returning to FIG. 4, analog sensors 116 include seat tilt sensor 224 of FIG. 1A. Digital sensor 1 in Figure 4
14 includes inclinometers 274^ and 274B of FIG. 1A.

This device and solenoid have a buffer arm 230°232
Contains a solenoid latch to release.

A motor drive 62 is coupled to motors 66 and 68 for driving the wheels. Encoders 70 and 72 provide feedback on travel speed and direction. Feedback from encoders 70.72 is provided to system bus 48 via encoder interface 136. When the same motor is energized by a track lowering mechanism connected to one of the drives 64, it also drives that track. Drive 64 also controls the position and tilt of the seat. These drives include a pulse width modulation generator 56 coupled to system bus 48.
controlled via.

The operation of the stair-climbing wheelchair of the present invention will be described below with reference to the flowcharts of FIGS. 7A-7F. 7th ArM
is a mode indicating the transition between wheel mode A and track mode B! It is a diagram. In wheel mode, the wheelchair moves on four wheels and does not have the ability to go up or down stairs; in track mode, the ultrasonic transducer detects a sufficient inclination for the steepness of the stairs or user input At the request of , the endless track is lowered. Using a single ultrasound transducer for each direction, a microprocessor can calculate distance differences to detect vertical height variations. Multiple ultrasound transducers are used to increase reliability and reduce errors.

FIG. 7B is a diagram of the orbital mode condition. Normal condition! B
At C, the wheelchair moves along the horizontal ground, constantly checking the angle (ultrasonic transducer) for vertical falls, and checking the inclinometer 274^. The reading is adjusted by keeping the user in a vertical orientation. Small fluctuations are filtered out so the user never falls over.

Once an upward vertical inclination of the stairs is detected that is a sufficient incline, the wheelchair transitions to the stair or ramp mode D shown in FIG. 7D. When a vertical tilt with respect to the chair or ramp is detected, the wheelchair transitions to program state E, detailed in FIG. 7C.

For the stair descent ramp shown in Figure 7C, the first step F ensures that the wheelchair is in track mode. Next, the slope of the staircase or ramp is calculated (step G)
. For stairs, the slope is measured by advancing the wheelchair and detecting the distance between the first two steps of the stairs. The slope can then be calculated using triangulation since the distance between the steps and the height of the steps are known.

Encoders 70 and 72 indicate the distance traveled and the ultrasonic
A sensor 76 indicates variations in step height. The angle of the ramp can be calculated by determining the ratio of variation to the variation in travel distance. If the ramp is too steep, further advancement is prohibited (step H).

If it is detected that the ramp or staircase is not too steep, the wheelchair seat is adjusted to the lowest safe angle at the top of the ramp (step I) or at the top of the staircase (step J).

The minimum safe angle (MSA) of the seat can be predetermined for the maximum inclination angle that the wheelchair can accommodate. 0 performed using the corrected limit value
M5A is the calculated angle at which the seat must be tilted to prevent the user or the seat from falling even if a further tilting motion fails. The angle may be smaller.

Alternatively, the MSA may be calculated separately for each angle of inclination, this calculation may be done each time or the values may be stored in a table, and the seat also includes a weight sensor; The table can also be modified to be accurate for each user or group of users.

Once the wheelchair has adjusted its seat to the MSA, the forward easy-down or buffer arm 236 is positioned at the top of the stair (step K); the forward easy-down is positioned by the retractable retention latch 234 shown in FIG. 1A. be done. The microprocessor checks sensor 270 to ensure that the easy down is no longer in its lower position. A separate sensor 233 may be used to confirm that the easy down is in its lower position, or gravity may be used.

After the easy down is placed, the chair is advanced and begins to roll (step L), the opening angle of the roll is detected by the inclinometer and the seat is also adjusted to keep the user perpendicular to the direction of gravity. During the roll, forward movement of the wheelchair is prohibited until it assumes a new angle. After the chair has settled down to the angle of the stairs, the easy down is retracted using a motor or actuator (Step M).

- Once the sensor 270 detects an easy down position in the upper position, the wheelchair is allowed to proceed. When the wheelchair reaches the bottom of the stairs, the inclinometer detects the change in angle and indicates that it is near the bottom of the stairs. The seat is adjusted to the normal position based on the inclinometer reading (step N), and once the chair is in the normal position, the wheelchair is in normal trajectory mode (step F).

FIG. 7D shows the stair climbing or up-ramp mode of the program, in which the forward ultrasonic transducer or inclinometer detects the incline and prevents the wheelchair from advancing up the incline. The user rotates the wheelchair and approaches the incline in the opposite direction. As the wheelchair begins to climb an incline or staircase, the inclinometer 274 detects the climbing angle and detects nasal intervention. The seat is adjusted accordingly (step ○), and if the nose is not detected and indicates a ramp, climbing of a predetermined steepness is allowed for that ramp. If the inclination angle becomes too large, indicating that the inclination is too large, or if the nose of the next step is not detected, further climbing movements are prohibited (step P), otherwise, The wheelchair continues up the ramp and makes further movements to keep the seat perpendicular to gravity. When the rear ultrasonic transducer detects landing on the top of a stair or ramp, the rear easy-down or buffer arm 32 is positioned in the same manner as the front easy-down (step R).

Landing is indicated by the failure of another step rise beyond the chair to be detected.

The inclinometer detects when the wheelchair moves backwards and the wheelchair rolls backwards to land as the ease-down cushions this motion. There is no need to stop the backward motion of the wheelchair at this time; the inclinometer simply detects the rolling, adjusts the seat accordingly, and detects when the wheelchair moves forward until it assumes a horizontal position. At this point there is no risk of rolling, so there is no need for the seat to move too early to the MSA. At this point, the easy down retracts like the forward easy down (step T). The rolling spacer is constantly adjusted to keep the user in a vertical position, after which the wheelchair enters the normal trajectory mode.

FIG. 7E shows in detail the diagram of the retracted condition of the egee-down; - Once the retract command is received, the motor or actuator causes the egee-down to be retracted (step U). Next, the up sensor 2F0 is checked to confirm whether the easy down lever has been drawn in properly (step 2). The actuator then disconnects and the retaining latch 23
4 is inserted (step W), and the easy down is ready for the next placement.

FIG. 7F shows a diagram of the easy down arrangement. When the placement command is issued, the solenoid actuates the latch 234, which releases the ease down (step Y)0
Sensor 270 is then checked and detects that the easy down is no longer in the up position (Step Z). The solenoid that causes the latch to retract is then turned off (step AA).

Figures 8A and 8B illustrate calculation of rotational skew by an electronic controller according to the present invention. The Y axis shown in FIGS. 8A and 8B extends from the rear to the front of the vehicle 110. Y
The shaft extends from side to side of the vehicle and enters and exits the page of FIG. 8A. FIG. 8B is a top view of FIG. 8A, showing the Y-axis more clearly. When the vehicle 110 is on the stairs 300, the variation from the Y axis should be the slope A of the stairs if the vehicle is aligned with no variation in the Y axis.

A pair of inclinometers 274^ and 274B are connected to the Y-axis and Y-axis, respectively.
Detects fluctuations in the vehicle's footme from the axle. Vehicle 11
When 0 moves up and down the stairs 300, it is desirable that it move in a straight line and that it does not deviate from the sides of the stairs in one direction or the other. One way to monitor this condition is to provide a three-axis gyro that provides the three-dimensional position of the vehicle. In the present invention, the inclinometer is monitored as if there were no variations from the Y axis and the vehicle was traveling in a straight line as long as the variation from the Y axis was equal to the slope of the stairs. Variations in the Y axis indicate that the vehicle is moving laterally.

The rotational skew, ie the lateral movement of the vehicle descending the stairs, can be detected from the inclinometer readings. The value of X changes according to the variation of A with respect to a predetermined amount of rotational skew R with Y being a constant. Furthermore, if R and A are constant, then X will vary as Y changes.

The calculation of rotational skew is shown in the flowchart of FIG. 9A. Two types of parallel calculations I and ■ are shown. In one calculation, the slope of the stairs is updated from the Y-axis longitudinal inclinometer (step A), which means that the horizontal axis X inclinometer reading is zero and stable and one step below the slope. If you show that there is no change from the straight line trajectory, then execute it.
Therefore, the inclinometer reading in the longitudinal Y axis must be equal to the slope of the stairs. Next, the maximum lateral slope is calculated (step B). This is done using a skew of up to 15 degrees and the current slope of the stairs. At the same time, separate calculations are made to regulate the skew movement (step C). This is done if the lateral slope reading is greater than the calculated maximum lateral slope. In this state, the vehicle is prevented from traveling in any direction other than the direction that reduces skew.

Figures 9B-9D illustrate the calculation of the skew angle.

FIG. 9B shows the wheelchair 110 on a staircase 300, and the skew angle is defined as the angle between line B, which is the direction the wheelchair is pointing, and line A below the center of the staircase.

FIG. 9C is a top view of the inclined surface shown in FIG. 9B. It can be seen that the following relationship holds true.

Co5(skew angle θ)=A/B Co5(90−skew angle θ)=A,,/C FIG. 9D shows the angle of FIG. 9C projected to the ground level. A line indicates the distance from the center of the wheelchair on the slope to the ground level below the slope. Three types of angles, longitudinal angle,
Stair angles and lateral angles are shown. Given the staircase angle and a maximum skew angle of 15°, the corresponding lateral angle can be calculated as follows:

5in (lateral angle θ>=D/C=<D/^>/(C/
^) □5in (stair angle) XCO5 (75°) Therefore,
The maximum lateral inclination is the lateral angle θ□5in-' (Sin (stair angle θ)
C05 (75°)) If the measured value from the X-axis inclinometer is zero or extremely small while the vehicle 110 is on the stairs 300, then any variation in the Y-axis inclinometer can be calculated as the inclination of the stairs. It is possible to more accurately read the slope of the stairs.

Therefore, a zero rotation skew in which the value of A is updated at these points will not result in a change in the Y-axis direction without a corresponding change in the X-axis direction.

Figures 10A-10C illustrate the operation of the two rear sensors. The lower sensor 302 is mounted at an angle of about 10 degrees to the vertical, so that the ultrasound beam 3
04 is oriented outwardly at an angle approximately 10 degrees below the horizontal. A second sensor 306 is mounted higher and its ultrasound beam 308 is directed approximately 40 degrees downward relative to the horizontal.

Beam 304 from sensor 302 is shown off riser 310 . A processor in vehicle 110 analyzes the sensor outputs and determines the range for riser 310 . As the vehicle 110 approaches the stairs 300, the processor learns the distance traveled by the chair from sensor inputs from the motors driving the vehicle's wheels. The processor recognizes the riser as being in a fixed position. As the vehicle approaches, beam 304 moves upward along riser 310 until it passes nose 312, as shown in FIG. 10B. At this time, the distance detected by the sensor 302 jumps to indicate the position of the nose. The exact location of this jump is obscured by a number of effects, including the carpet on the stairs that deflects the beam around the nose 312.

As shown in FIG. 10, a second beam 308 from sensor 306 is directed toward riser 31 as the vehicle approaches the stairs.
Detects 0. As shown in FIG. 10C, beam 308
Also, it passes through the nose portion 312 with a jump in the detection distance. Data from sensor 306 is then correlated with data from sensor 302 to accurately determine the location of nose 312.

setting a window using readings from sensor 302;
Readings from sensor 306 can be examined within the window to detect the position of the nose. The greater downward angle of the beam from sensor 306 causes the beam to pass more slowly through the nose, providing a more accurate indication.

For the same reason, the jump distance is not as sharp, making initial detection of the nose from sensor 302 important. Identification of the nose is particularly important for deck-type stairs that do not have a rising part.

The processor of the vehicle 110 has programmed the physical and geometric characteristics of the vehicle so that - once the position and height of the nose 312 is known, the vehicle can either detect the next stage or In contrast, it is possible to detect where the vehicle can crawl and begin climbing the nose portion 312 before it becomes necessary to deploy the W1 impact arm. By knowing exactly the position of the nose over which the wheelchair is moving, it is possible to know how far the wheelchair can move backwards before entering a situation that requires rolling. During this time the vehicle can move in search of the edge of the next stage.

In one embodiment, the processor may store in memory a representative map of a typical staircase shape, and then store the resulting data rather than analyze the data with a computationally complex algorithm. Can be adapted to patterns.

FIG. 11 is a flowchart illustrating the process of detecting the type of stair detected. The nose of the first step is detected as the wheelchair moves backwards towards the stairs (Step A).The inclinometer is then monitored to detect if the wheelchair begins to climb the stairs.The incline of the stairs is then monitored. is calculated, and the predicted position of the nose of the next stage is detected (step C).

If the nose of the second step is detected as expected, we have encountered a normal staircase (step D); if the second nose is not detected, this means that only the -step is encountered. mosquito,
Or indicate that it is a curb (step E). In this case, easy down is the key! to allow the wheelchair to roll to the top of the curb.

As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics using a single forward ease down. be able to. Accordingly, the foregoing disclosure of preferred embodiments of the invention is illustrative and is not intended to limit the scope of the invention as claimed.

Rj= K, JRj, φ・O, −N Corrected control stick rotation value ELj=”j'j−CLj, S=
O, -N Left motor observation error ERj=
Tj+Rj-CRj, S=0. -N Observation error of right motor p1 = K, ELQ
Left motor proportional correction Left motor proportional correction PR'' ReRO.

IL: K isum+(EL J, t□0, -N)
Left motor integral correction IR = Jsum (E
Rj,j・0. -N) Right side motor integral correction OL
= Kd (CLO-C14) Left motor differential correction DR = K, 1 (CRO-CR-1)
To the right motor differential correction M1=, (ERO
-ELO) Left side motor 9/motor U positive M
l(□ K, (ELO-ERO)
Right motor/motor correction XLO = XL-10 to 5 (
P1+IL+J,"t4L) New left motor Hower XR□-XH-1+ to 8 (PR+IR+DR+MH)
New right hand motor hower therefore XLO and XRO
is in the range of (-255, +225).

APPENDIX ■ FILL IN LUGORISM JL This appendix describes the algorithm used to filter the control column readings read from the analog-to-digital converter in the command module.

The filtered reading results are sent to the control module for execution.

Otogeki Kogyo 7’A note The positive X direction is the straight direction of the control stick.

The positive Y direction is the leftmost control column direction.

1, a of XfjY read from m A/D converter
It is converted to XfjY by a. negative number S
The S character is always shown in two's complement form. Conversion is MS of numbers
This is executed by performing complement processing on B.

It can be done.

If the MSB of the signed number is 1, set the carry, otherwise reset. A carry shifts the number one bit to the right.

For this reason, a negligible amount of hysteresis is added to (-12
Convert the number range from 8 to +127) to (-64 to +63).

3. After the above process, Xsh+jYsh is sieved by a real-time digital low-pass filter with n-th wheel=4.

The cut-off frequency of this filter (from approximately 1.5) 1z to 15Hz is stored as a parameter in the key PROM. This kind of filter is responsible for patients with involuntary tremor disorder.

XSh and Ysh should be filtered separately to remove the quivering alternating current (AC) component in both the transform and rotary scalers, leading to the desired result.

The resulting values of X and Y are X r + J Y
It is called r.

Xf+jY, is mapped either via a table or another algorithm to
+jYf is generated.

a. Slight deflection of the control stick causes the values of Xf and +jYfm to deviate relatively small. This increases the resolution of the system in the region close to the zero position of the control stick.

The large deflection of the control stick causes the values of Xf and +jYf to deviate relatively largely. This reduces the resolution of the system in regions away from the control column zero position.

This type of mapping allows the user to have fine control over the speed of the wheelchair, for example in office areas where the wheelchair is moving very slowly and requires precise positioning by the user.

A typical mapping can be obtained from the equation below.

X(,=Rf,XCo5(θf+e) Low speed mode by effectively treating the speed mode pit as another bit of control stick resolution.

In this way, for example, the control means receives (X, Y) = (
A value of +63.0) means that the control means is attempting to drive the wheelchair forward at 3 mph if in low speed mode or 6 mph if in high speed mode.

Maximum velocity measurements can be made either in the command module or in control mode.

6.1 The maximum acceleration of a is firstly automatically limited by the position of the poles of the system, ie by the slowness of its functioning.

The following limits the rate of change of X and Y separately.

If the absolute value of y(k)-y(k-1) is A, then s Ba, Y,,d=Y(k-1)1±A,.

The sign of A is the same as the sign of (Y(k)-Y(k-1>) character. or Yfed = Y (k) Do the same for X using A Ta Generate Xfmd.

At faster conversion speeds, the value of A needs to be lowered to 7m, and at -paper speeds it can be increased. Therefore, the following steps are also added to improve the Y value.

Yf,,I=Yf,dxK,r/current conversion speed 7,
゛ The rearward speed should be much lower than the forward speed;
This is done by multiplying the X and Y values obtained from the above process by a constant if X turns out to be negative. This constant is also stored in the key FROM.

In this way, if X is negative, then X+jYcur=Krev×(Xf, d+jYf, d)
Cu" Or Xcur+jY11r-IX(Xf, d+jYf1d)
However, K is a constant of the backward speed factor and is stored in the key ev PROM. A typical K ev value may be between 0.1 and 0.25, and (Xcur+jYe
ur) is the value communicated to the control module.

[Brief explanation of drawings]

Fig. 1A is a perspective view of a motor-driven PTV using the present invention, Fig. 1B is a diagram of the piston and cylinder device for easy down shown in Fig. 1A, and Fig. 2 is a block diagram of the electronic control device of the present invention. 3 is a block diagram of the command module shown in FIG. 2, FIG. 4 is a block diagram of the control module shown in FIG. 2, and FIGS. 5 and 6 are block diagrams of the command module shown in FIG. 1. Figures 7A-7F are flowcharts showing the operation of the wheelchair shown in Figure 1A during lifting and lowering of the wheelchair; Figures 8A and 8;
Figure B is a diagram showing rotational skew calculation, Figure 9A is a flowchart showing rotational skew calculation, Figures 9B to 9D are diagrams showing skew angle calculation, and Figures 10A to 10C are stairs at the rear. identify 2
FIG. 11 is a flowchart of the stair type identification process. In the figure, 210... Wheelchair 212... Endless track 2
14... Seat part 222... Actuator 224, 226, 228^, B... Sensor 230.
232...Buffer arm 254...Reservoir 274
^, B... Inclinometer 302, 306... Sensor 3
04,308・Beam 310...Stair rising part 312...Stair nose part Attorney Patent attorney Kyo Yu Asa 3'. (4 other people) Japan G. E valve ° jaw force, Gino Nishiki” bJ
Neji Genun's f-n, "Kami U's J8 Seki f"lk, 7E,
″RING°'7F\8Fl cr, g A. Fl(i, g8°[1cr, 10.4°FICr, IOC and\

Claims (1)

[Claims] 1. a first front ranging sensor; a second rear ranging sensor; in response to the sensors, determining the slope of the stairs and controlling the motor of the personal transport vehicle to achieve a predetermined range; electronic means for preventing movement on stairs that exceed geometric characteristics; and tilting the seat of the vehicle in response to a determined inclination from the electronic means to correct the center of gravity of the vehicle and its user. means for preventing said vehicle from tipping over on said stairs; and providing said electronic means with a key code to operate said vehicle and providing constants for an algorithm used by said electronic means to prevent said vehicle from tipping over. a removable programmable memory defining an operating envelope for a stair-climbing personal transport vehicle. 2. A vehicle according to claim 1, characterized in that said electronic means includes means for preventing movements other than forward descent and backward climbing on stairs. 3. The vehicle according to claim 1, further comprising: a first inclinometer measuring inclination along a Y-axis extending from front to rear across the vehicle; and an X-axis extending from one side of the vehicle to another side. and means for determining a rotational skew of the vehicle from the measured inclination from the X-axis and the measured inclination from the staircase inclination. Personnel transport vehicle. 4. The vehicle according to claim 1, further comprising: a third rear sensor attached at a certain angle with respect to the second rear sensor; and a third rear sensor coupled to the second and third sensors; A personal transport vehicle characterized in that it includes means for detecting the nose of a staircase from the output of said third sensor within a window defined by said third sensor. 5. a ranging sensor; electronic means responsive to said sensor to determine the slope of a stair; a first inclinometer measuring slope along a Y-axis extending from front to rear across said vehicle; and one of said vehicles; a second inclinometer for measuring inclination from an X-axis extending from one side to another; and determining the rotational skew of the vehicle from the measured inclination from the A stair-climbing personal transport vehicle characterized by comprising: means for determining. 6. The vehicle of claim 5 further comprising control means for adjusting the direction of the vehicle in response to the rotational skew. 7. A first ranging sensor, a second ranging sensor attached at a certain angle with respect to the first ranging sensor, and the first and second ranging sensors.
A stair-climbing personal transport vehicle, characterized in that it includes means coupled to a sensor for detecting the nose of a stairway from the output of the second sensor within a window defined by the first sensor. . 8. The vehicle according to claim 7, wherein the second sensor is mounted higher than the first sensor and points downward than the first sensor. 9. a first front ranging sensor; a second rear ranging sensor; and a staircase that determines the slope of the stairs in response to the sensors and controls a personal transport vehicle motor to go over a predetermined slope. electronic means for preventing movement on the stairs and preventing movement other than forward descent and backward ascent movements on the stairs; and for tilting the seat of the vehicle in response to a determined inclination from the electronic means; means for modifying the center of gravity between the vehicle and the user to prevent said vehicle from tipping over said stairs; providing said electronic means with a key code to enable said vehicle to operate; and providing an envelope of operation of said vehicle; and a removable programmable memory providing constants for an algorithm used by said electronic means to define. 10. a first front ranging sensor; a second rear ranging sensor; and determining the slope of the stairs in response to the sensors, and controlling the motor of the personal transport vehicle to move on the stairs over a predetermined slope. and electronic means for preventing the vehicle from tipping over on the stairs by tilting the seat of the vehicle in response to the determined tilt from the electronic means to correct the center of gravity between the vehicle and the user. providing a key code to said electronic means to enable said vehicle to operate and providing constants for an algorithm used by said electronic means to define an envelope of operation of said vehicle; a first inclinometer for measuring tilt along a Y-axis extending from front to rear across the vehicle; and a first inclinometer measuring tilt from an X-axis extending from one side of the vehicle to the other. The second to measure
A stair-climbing personal transport vehicle, comprising: an inclinometer; and means for determining a rotational skew of the vehicle from the measured inclination from the X-axis and the measured inclination from the inclination of the stairs. . 11. a first front ranging sensor; a second rear ranging sensor; and determining the inclination of the stairs in response to the sensors, and controlling the motor for the personal transport vehicle to move over the stairs over a predetermined inclination. electronic means for preventing movement; and in response to a determined inclination from said electronic means, the seat of said vehicle is tilted to modify the center of gravity of said vehicle and user to prevent said vehicle from tipping over said staircase. and a removable means for providing a key code to said electronic means to enable said vehicle to operate and for providing constants for an algorithm used by said electronic means to define an envelope of operation for said vehicle. a third rear sensor mounted at an angle to the second rear sensor; and a third rear sensor coupled to and defined by the second and third sensors; and means for detecting the nose of a staircase from the output of the third sensor within the window. 12. at least one ranging sensor for detecting a change between an inclined surface and a generally horizontal surface; a buffer arm disposed on one of the surfaces; and a buffer arm coupled to the vehicle to detect a change between a generally horizontal surface. A stair-climbing personal transport vehicle, comprising: means for cushioning the vehicle from overturning; and means for locating the shock absorbing arm in response to the sensor. 13. The vehicle of claim 12, further comprising electronics responsive to the sensor to determine the slope of the stairway and to control a motor of the vehicle to prevent movement on the stairway above predetermined geometric characteristics. A personal transport vehicle characterized in that it includes a means. 14. The vehicle of claim 13, further comprising: tilting the seat of the vehicle in response to the determined tilt from the electronic means to modify the center of gravity of the vehicle and the user; A person-transport vehicle characterized in that it includes means for preventing the vehicle from overturning. 15. A vehicle as claimed in claim 13, further comprising an algorithm used by the electronic means to provide a key code to the electronic means to enable the vehicle to operate and to define an envelope of operation of the vehicle. A personal transportation vehicle comprising a removable programmable memory that provides a constant amount of information. 16. A vehicle according to claim 13, characterized in that the electronic means includes means for preventing movements other than forward descent and backward ascent on stairs. 17. A vehicle according to claim 12, wherein the means for damping falls comprises: a fluid-filled tube connected to one of the vehicle and the damping arm; and a fluid-filled tube extending to and not connected to the tube. A personal transportation vehicle comprising: a piston connected to the vehicle and one of the shock arms; and means for regulating the flow rate of the fluid and limiting the compression rate of the tube and piston combination. 18. The vehicle of claim 17 further including a solenoid actuated latch for retaining the shock arm in an upward position. 19. The vehicle of claim 17 further comprising a fluid reservoir coupled to the tube. 20. A vehicle according to claim 17, characterized in that the restricting means comprises a unidirectional fixed orifice in the piston. 21. at least one ranging sensor for detecting a change between an inclined surface and a generally horizontal surface; a buffer arm disposed on one of said surfaces; said buffer arm coupled to said vehicle; means for dampening the fall of the vehicle; means responsive to the sensor for locating the dampening arm; and responsive to the sensor for determining the slope of a stairway and controlling a motor of the personal transport vehicle to provide a predetermined response to the vehicle. A stair-climbing personal transport vehicle characterized by comprising: electronic means for preventing movement on stairs that go over an incline; 22. at least one ranging sensor for detecting a change between an inclined surface and a generally horizontal surface; a buffer arm disposed on one of said surfaces; and said buffer arm coupled to a personnel carrier and directed toward one of said surfaces. means for cushioning a fall of the vehicle; means for positioning the damping arm in response to the sensor; and determining a slope of a staircase in response to the sensor and controlling a motor of the vehicle to achieve a predetermined slope. electronic means for inhibiting movement over a stairway over a stairway; and in response to a determined inclination from said electronic means, tilting a seat of said vehicle to modify the center of gravity of said vehicle and user to prevent movement over said stairway; means for preventing the overturning of said vehicle; and providing said electronic means with a key code to enable said vehicle to operate and for an algorithm used by said electronic means to define an envelope of operation of said vehicle. A stair-climbing personal transport vehicle comprising: a removable programmable memory for providing a constant value; 23. A sensor for detecting the inclination angle of a certain surface before the vehicle traverses the surface; and means for adjusting the inclination of the seat based on the inclination; and in response to the sensor, the adjusting means 1. A stair-climbing personal transport vehicle having a seat, comprising: means for preventing movement of the vehicle on slopes greater than a predetermined steepness until the seat is tilted to a predetermined minimum angle. 24. The vehicle of claim 23, wherein the minimum angle is calculated to change the center of gravity of the vehicle and the user sufficiently to prevent the vehicle from tipping over on the slope. An anti-personnel transport vehicle. 25. The vehicle of claim 23, further comprising: means for determining an angle of inclination of the vehicle; and, in response to the angle of inclination, adjusting the inclination of the seat to keep the seat horizontal with respect to the center of gravity. A personal transport vehicle further comprising means for: 26. The vehicle according to claim 25, wherein the means for adjusting the inclination of the seat includes a shaft connected to a support part of the seat, and a seat tilting motor that drives the shaft. An anti-personnel transport vehicle. 27. The vehicle according to claim 23, further comprising a position sensor that detects the inclination of the seat. 28. The vehicle according to claim 23, wherein the sensor that detects an angle includes a first sensor that detects a distance traveled by the vehicle, and a first sensor that detects a distance from itself to a point in front of the vehicle. a second sensor for measuring height, and wherein the angle of inclination is calculated by a combination of a change in the height measurement and a change in the distance traveled by the vehicle. 29. Means for detecting the angle of inclination of the surface before the vehicle traverses the surface, comprising: a first sensor for detecting the distance traveled by the vehicle; a second sensor that detects distance and measures height;
means for detecting an angle of inclination, the angle of inclination being calculated by a combination of the height measurement and the change in travel distance; a shaft connected to a support of the seat; and a seat tilting mechanism for driving the shaft. a motor; a third position sensor for detecting tilting of the seat; and means for detecting a tilt angle of the vehicle; means for adjusting the inclination of the seat according to the inclination angle to keep the seat of the seat horizontal with respect to the center of gravity until the seat tilting motor tilts the seat to a predetermined minimum angle; A stair-climbing personal transport vehicle having a seat, comprising: means for preventing movement of the vehicle above a slope of a predetermined steepness.